CN112359205B - Treatment method of platinum group metal beneficiation concentrate strengthened leaching solution - Google Patents

Abstract

The invention discloses a treatment method for strengthening leaching solution of platinum group metal ore concentrate, which adopts the process route of strengthening leaching solution-residual acid neutralization-active copper powder to replace precious metal-iron powder to replace copper-compressed air oxidation neutralization to remove iron, aluminum and chromium , a method for enriching precious metals and comprehensively recovering valuable metals. Compared with the prior art, in the valuable metal intermediate product obtained by the present invention, the precious metal is precious metal replacement slag, which contains 300 g/t of precious metal; the copper is sponge copper slag, which contains 88% copper; the nickel-cobalt is nickel-cobalt hydroxide slag , which contains 32% nickel and cobalt, and the recovery rate of valuable metal elements is more than 98%.

Description

A kind of treatment method of platinum group metal ore concentrate strengthening leaching solution

technical field

The invention relates to the technical field of rare and precious metal smelting, in particular to a processing method for strengthening leaching solution of platinum group metal ore concentrate.

Background technique

The platinum ore has the characteristics of large reserves of platinum group metals, high grade and stable thickness of the ore body. The reserves of platinum group metals are 412 tons and the basic grade is 5.22g/t. Platinum ore adopts the conventional semi-autogenous grinding + ball milling + grading grinding process, roughing + selection, roughing tailings regrinding and selection stage flotation stage grinding and flotation process, the annual output is about 82000 ton of precious metal concentrate, which contains 0.7-3.5% of Cr ₂ O ₃ and 12-21% of MgO. In addition to bringing about 9.5 tons of platinum group metals into the concentrate every year, the amount of nickel, copper and cobalt that can be brought in are 2492 tons, 1533 tons and 246 tons respectively.

When the platinum concentrate adopts the wet-strengthened leaching process, most of the elements such as copper, nickel, cobalt, iron, chromium, magnesium, and aluminum are leached into the leaching solution, and at the same time, a small amount of precious metals also enter the leaching solution. Therefore, the efficient recovery of nickel, copper and cobalt is of great significance.

The acid leaching solution of the above-mentioned complex co-associated platinum group noble metal beneficiation concentrate contains Ni, Cu, Co valuable metal element ions, as well as a small amount of Pt, Pd, Rh, Ir, Os, Ru, Au, Ag precious metal element ions, In addition, there are a large amount of impurity element ions such as Fe, Cr, Mg, Si, and Al, and H ₂ SO ₄ . Among them, most of Fe and Cr exist in the form of Fe ³⁺ and Cr ⁶⁺ respectively.

Due to the low concentration of valuable metal ions in the solution, many types and high concentrations of impurity element ions, it is necessary to choose an economical and reasonable process. Using the enhanced leaching solution of platinum and palladium flotation concentrates as raw materials, the precious metals, nickel and cobalt are separated and recovered. The separation and recovery process of valuable metal elements such as copper and precious metals is very meaningful.

SUMMARY OF THE INVENTION

In view of the deficiencies of the above-mentioned prior art, the present invention provides a processing method for strengthening the leaching solution of platinum group metal ore concentrate.

The present invention is achieved through the following technical solutions.

A processing method for strengthening leaching solution of platinum group metal ore concentrate, characterized in that the processing method comprises:

(1) The reducing agent sodium sulfite is added to the enhanced leaching solution of the platinum group metal ore concentrate to carry out a pre-reduction reaction to reduce Fe ³⁺ and Cr ⁶⁺ in the solution to Fe ²⁺ and Cr ³⁺ respectively, and then use sodium carbonate or limestone Neutralize the residual acid, adjust the pH of the pre-reduction solution to 1.5-2.0, and obtain the first filtrate and the first filter residue through solid-liquid separation;

(2) Replacing precious metals with active copper powder: adding active copper powder to the first filtrate obtained in step (1) to replace precious metals, to obtain a replacement liquid and a replacement slag;

(3) adding iron powder to the post-replacement solution obtained in step (2) to carry out the reaction of replacing copper, and obtaining the second filtrate and the second filter residue through solid-liquid separation;

(4) the second filtrate obtained in step (3) is subjected to a one-stage oxidation precipitation iron-aluminum-chromium-arsenic reaction, after solid-liquid separation, and then a two-stage oxidation precipitation iron-aluminum-chromium-arsenic reaction, neutralizing the precipitated nickel in two stages After the cobalt reaction, tailings and tailings are obtained;

(5) neutralizing and precipitation manganese reaction of the tail liquid obtained in step (4), and finally obtaining neutralized tail liquid and neutralized tail slag through solid-liquid separation.

Further, the components of the leachate include: Au 0.003～0.004g/L, Pd 0.0045～0.0050g/L, Pt 0.00092～0.00098g/L, Rh 0.0012～0.0015g/L, Ir 0.0015～0.0017g/L, Ni 2.02～2.03g/L, Cu 6.36～6.39g/L, Fe 9.62～9.63g/L, Co 0.057～0.059g/L, As 0.0021～0.0026g/L, Cr 1.13～1.20g/L, Mg 6.22～ 6.32g/L, Al 2.60～2.63g/L.

Further, the amount of sodium sulfite added in the step (1) is the required amount for reducing Fe ³⁺ to Fe ²⁺ and Cr ⁶⁺ in the leaching solution to Cr ³⁺ , and the amount of sodium sulfite added is 78.7-78.9g /L solution (that is, 78.7～78.9kg/ ^m3 solution), the pre-reduction reaction temperature is 60℃～75℃, and the prereduction reaction time is 60min～65min; use sodium carbonate or limestone for residual acid neutralization: the reaction temperature is 60 ℃～65℃, the reaction time is 60min～65min.

Further, the reaction process of replacing precious metals with copper powder in step (2) is as follows: after the first filtrate obtained in step (1) is heated to 75°C to 85°C, active copper powder is added for stirring, and the active copper powder is Addition amount (wet weight) 12～16g/L solution (i.e. 12～16kg/ ^m3 solution), control potential value is 350mv～400mv, control end point pH 2.5～2.8, after reaction time 60min～65min, stop stirring, wait for temperature When the temperature drops to 60℃～65℃, solid-liquid separation is carried out.

Further, the active copper powder is obtained by adding zinc powder to a copper sulfate solution for replacement.

Further, the process of replacing the copper powder with the iron powder in the step (3) is as follows: the post-replacement solution obtained in the step (2) is heated to 75°C to 85°C, and then the iron powder is added, and the added amount of the iron powder is 10.4°C. ～16 g/L solution, control the potential value of 0～100mv, stop stirring after the reaction time is 60min～120min, and carry out solid-liquid separation when the temperature drops to 60℃～65℃.

Further, the step (4) one-stage oxidation precipitation reaction process is as follows: first, the second filtrate obtained in step (3) is heated to 70 ° C ~ 75 ° C, and compressed air is introduced, and the flow rate of the compressed air is 100 °C. -130 liters/hour, add calcium carbonate slurry with a concentration of 20%-21%, control pH 3.5 to 3.8, stop stirring after 100 to 180 minutes of reaction time, and perform solid-liquid separation when the temperature drops to 60 °C to 65 °C , obtain the third filtrate and the third filter residue (the third filter residue is waste residue); the second stage of oxidation precipitation is to heat the third filtrate to 70 ℃ ~ 90 ℃, add the concentration of 10% sodium carbonate solution, control the reaction time 2h ~ 2.5 h, controlling the pH of the end point to be 4.6-4.8, obtaining a fourth filtrate and a fourth filter residue through solid-liquid separation, and the fourth filter residue is returned to step (1) for neutralization reaction.

Further, the step (4) two-stage neutralization and precipitated nickel-cobalt reaction process is: one-stage precipitation of nickel-cobalt is to heat the fourth filtrate to 60 ℃～65 ℃, add sodium hydroxide solution dropwise, adjust the endpoint pH of the solution to 7.5. 0～7.5, the total reaction time is 120min～180min; the second stage of precipitation of nickel and cobalt is to heat up the liquid after the first stage of precipitation of nickel and cobalt to 70 ℃～90 ℃, add sodium hydroxide solution dropwise, control the pH of the end point of the solution to 8.0～8.2, the total reaction The time is 120min-180min, and the tailings and tailings are obtained through solid-liquid separation (the tailings are waste).

Further, the concentration of the sodium hydroxide solution is 5%.

Further, the step (5) is to raise the temperature of the tail liquid obtained in the step (4) to 45°C to 50°C, and feed compressed air, the flow rate of the compressed air is 100 to 130L/h, and the concentration added is 20%. The pH of the tail liquid is adjusted to 8.5~9, the reaction time is 2h~2.5h, and finally the neutralized tail liquid and the neutralized tail slag are obtained by solid-liquid separation.

Beneficial technical effects of the present invention: The present invention provides a process route for strengthening leaching solution-residual acid neutralization-replacement of precious metals by active copper powder-replacement of copper by iron powder-compressed air oxidation neutralization to remove iron, aluminum and chromium, enriching precious metals and comprehensive recovery Valuable metal method. Compared with the existing technology, it has the following advantages:

(1) the valuable metal intermediate product that the present invention obtains, the precious metal is precious metal replacement slag, wherein contains precious metal 300g/t; Copper is sponge copper slag, wherein copper-containing 88%; Nickel cobalt is nickel hydroxide cobalt slag, wherein nickel-containing Cobalt 32%, the intermediate product is easier to be processed in the next step.

(2) The content of valuable metal elements in the neutralized tail liquid is lower than the lower limit of instrument analysis, namely ≤ 0.0002g/L, and the content of valuable metal elements in Fe-Al-Cr slag and neutralized magnesium slag obtained by one-stage oxidation precipitation reaction is low ( All ≤0.1%), the recovery rate of valuable metal elements is more than 98%.

Description of drawings

Fig. 1 is a process flow diagram of the present invention.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Example 1

A method for treating high-chromium and high-magnesium platinum group metal ore concentrate strengthening leaching solution, which comprises the following steps:

The leachate composition includes: Au 0.003g/L, Pd 0.0045g/L, Pt 0.00092g/L, Rh 0.0012g/L, Ir 0.0015g/L, Ni 2.02g/L, Cu 6.36g/L, Fe 9.62g/ L, Co 0.057g/L, As 0.0021g/L, Cr 1.13g/L, Mg 6.22g/L, Al 2.60g/L.

Step 1. Solution pre-reduction and solution residual acid neutralization

The reducing agent sodium sulfite is added to the enhanced ^leaching solution ^of platinum group metal ^ore concentrate, and the pre-reduction reaction is carried out. It is Fe ²⁺ and Cr ³⁺ , and then neutralized with sodium carbonate or limestone. The residual acid content in the leaching solution is generally about 30-40g/L. (first filtrate) and pre-reduction residue (first filter residue); the reduction and neutralization temperatures are both 60° C., and the reduction and neutralization times are both 60 min.

Step 2. Precious metal replacement

Take a certain amount of platinum and palladium flotation concentrate for enhanced leaching and pre-reduced solution, namely the first filtrate, add it into a beaker or reactor, start stirring, adjust the rotational speed, and start adding the reducing agent active copper powder after the temperature is raised to a set temperature of 75°C. In the beaker or reactor, the added amount of active copper powder (wet weight) is added according to 12g/L solution, and the timing is started. After the predetermined potential value of 350mv is reacted for a predetermined time for 60min, the end point pH value is controlled to 2.5, and the stirring is stopped to stop the reaction. When the temperature drops to about 60°C, the pulp is taken out for filtration and washing, the solid sample is dried and then subdivided for sampling and analysis.

Table 1 Result of replacing precious metal with active copper powder

Step 3. Iron powder replaces copper

Use iron powder to replace copper ions in the solution, take a certain amount of precious metal to replace the solution, add iron powder according to 10.4 g/L solution, add it into a beaker or reactor, turn on stirring, adjust the speed, and heat up to the set temperature of 75 After ℃, start adding iron powder into the beaker or reactor, and start timing until the predetermined potential value is 56mv. After the predetermined reaction time of 60min, stop stirring and stop the reaction. When the temperature drops to about 60℃, take out the pulp, filter and wash, and get Iron replacement liquid (second filtrate) and iron replacement slag (second filter residue). After the solid sample is dried, the sample is divided and analyzed, and the volume of the solution is measured and analyzed for the content of base metals. The endpoint pH is 2.5, and the results are shown in Table 2.

Table 2 Results of copper replacement by reduced iron powder

Step 4. Staged oxidative hydrolysis precipitation of iron, aluminum, chromium, arsenic

The leaching solution contains a large amount of Fe2+, Al3+, Cr3+, H3AsO3, which must be removed in advance. Since the iron-aluminum-chromium slag is easy to adsorb and precipitate nickel-cobalt ions during the precipitation of iron-aluminum-chromium, in order to ensure the recovery rate of nickel-cobalt, a two-stage oxidation precipitation process of iron-aluminum-chromium is adopted.

Take a certain amount of iron-replaced solution, namely the second filtrate, put it into a beaker or reactor, turn on stirring, adjust the rotational speed, heat up to a set temperature of 70°C, and start to introduce compressed air, and add 20% calcium carbonate slurry into the beaker Or in the reactor, and start timing, a stage of oxidation and removal of iron, aluminum, chromium, arsenic to a predetermined pH value of 3.5, after the predetermined reaction time of 100min, stop stirring, stop the reaction, and when the temperature drops to about 60 ℃, take out the pulp, filter and wash to obtain a stage The iron-removed liquid (third filtrate) and a section of iron-aluminum slag (third filtrate). After the solid sample is dried, the sample is divided and analyzed, and the volume of the solution is measured and analyzed for the content of base metals and precious metals.

Process parameters: temperature 70°C, time 100min, compressed air flow 100L/h, the results are shown in Table 3.

Table 3 results of precipitation of iron, aluminum and chromium in the first section of table 3

The liquid after the first-stage iron removal, that is, the third filtrate, is used for the second-stage deep removal of iron, aluminum, chromium, and arsenic. The neutralizing precipitant uses 10% sodium carbonate solution, and the end point pH is 4.6 to 4.8. The iron, aluminum and arsenic slag (fourth filter residue) is returned to the pulp for neutralization.

Process parameters: The second-stage air oxidation precipitation of iron, aluminum and chromium adopts a relatively high pH of 4.6 to 4.8, a fixed temperature of 70 ° C, a time of 120 minutes, and a compressed air flow of 100 L/h. The results are shown in Table 4.

Table 4 Results of deep iron, aluminum and chromium removal in the second stage

Step 5. Neutralize and precipitate nickel-cobalt in stages

A stage of sodium hydroxide precipitation of nickel cobalt

Process parameters: the concentration of sodium hydroxide solution is 5%, the temperature is 60 ° C, the second-stage iron, aluminum and chromium solution is 1.5L of the fourth filtrate, the sodium hydroxide solution is added dropwise, the pH of the solution is adjusted, the total reaction time is 120min, control The endpoint pH of the solution was 7.0, and the results are shown in Table 5.

Table 5 results of sodium hydroxide precipitation nickel cobalt

Second stage nickel cobalt precipitation

Process parameters; the concentration of sodium hydroxide solution is 5%, the temperature is 70 ° C, the post-precipitation solution of nickel and cobalt is 1.5L, the sodium hydroxide solution is added dropwise, the pH of the solution is adjusted, and the solution sample is taken every 30min to analyze the concentration of nickel and cobalt and the precipitation rate, The total reaction time was 120 min, and the endpoint pH of the control solution was 8.0. The results are shown in Table 6.

Table 6 results of nickel and cobalt precipitation in the second stage

Step 6. Neutralization of tail liquid and precipitation

The solution after nickel-cobalt replacement contains a large amount of magnesium and other metal ions. Lime milk can be added to neutralize the precipitated magnesium and manganese, so that the pH of the solution is adjusted to 8.5-9, and compressed air is introduced to oxidize the harmful element ions in the solution. Remove to make the solution discharge standard.

Take 2.0L of the second-stage nickel-cobalt precipitation solution, heat it up to 45°C, introduce compressed air with a flow rate of 100L/h, adjust the pH of the solution to 8.5 with 20% lime milk (discharge wastewater pH 6-9), the reaction time is 2h, The pH at the end point of tail liquid neutralization and the composition of tailings were investigated. The results are shown in Table 7.

Table 7 tail liquid neutralization results

Example 2

A method for treating high-chromium and high-magnesium platinum group metal ore concentrate strengthening leaching solution, which comprises the following steps:

The leachate composition includes: Au 0.004g/L, Pd 0.0050g/L, Pt 0.00098g/L, Rh 0.0015g/L, Ir0.0017g/L, Ni 2.03g/L, Cu 6.39g/L, Fe9.63 g /L, Co 0.059g/L, As 0.0026g/L, Cr 1.20g/L, Mg 6.32g/L, Al 2.63g/L.

Step 1. Solution pre-reduction and solution residual acid neutralization

The reducing agent sodium sulfite is added to the enhanced leaching solution of platinum group metal ore concentrate to carry out a pre-reduction reaction. The amount of sodium sulfite added is 78.9g/L solution, that is, 78.9kg/ ^m3 solution, and Fe ³⁺ and Cr ⁶⁺ in the solution are respectively reduced to Fe ²⁺ , Cr ³⁺ , and then use sodium carbonate or limestone for neutralization, the residual acid content in the leaching solution is generally about 30-40g/L, adjust the pH of the pre-reduction solution to 2.0, and obtain the pre-reduced liquid ( The first filtrate) and the pre-reduced residue (the first filter residue); the reduction and neutralization reaction temperatures are both 65°C and time 65min.

Step 2. Precious metal replacement

Take a certain amount of platinum and palladium flotation concentrate for enhanced leaching and pre-reduced solution, namely the first filtrate, add it into a beaker or reactor, start stirring, adjust the rotation speed, and start adding the reducing agent active copper powder after the temperature is raised to a set temperature of 85 °C. In the beaker or reactor, the addition amount of active copper powder (wet weight) is added according to 16g/L solution, and the timing is started. After the predetermined potential value of 400mv is reacted for a predetermined time of 65min, the stirring is stopped, and the reaction is stopped, and the temperature is lowered to about 65 When the temperature is ℃, take out the pulp for filtration and washing, the solid sample is dried and then subdivided for sampling analysis, and the volume of the solution is measured and sampled to analyze the content of base metals and precious metals.

Process parameters: 40g of active copper powder (wet weight) was added, the replacement time was 65min, and the endpoint pH was 2.8.

Table 8 Result of replacing precious metal with active copper powder

Step 3. Iron powder replaces copper

Use iron powder to replace copper ions in the solution, take a certain amount of precious metal to replace the solution, add it into a beaker or reactor, start stirring, adjust the speed, and start adding iron powder at a rate of 16 g/L after the temperature is raised to a set temperature of 85 °C. Inside the beaker or reactor, and start timing, and after the predetermined potential value of 100mv is reached for the predetermined time of 120min, the stirring is stopped, and the reaction is stopped. When the temperature drops to about 65 °C, the slurry is taken out for filtration and washing to obtain the iron-replaced liquid (the second filtrate). ) and the slag after iron replacement (the second filter slag). After the solid sample is dried, the sample is divided and analyzed, and the volume of the solution is measured and analyzed for the content of base metals.

Process parameters: 32 g of reduced iron powder (dry weight) was added, the replacement time was 120 min, and the endpoint pH was 2.5. The results are shown in Table 9.

Table 9 Results of copper replacement by reduced iron powder

Step 4. Staged oxidative hydrolysis precipitation of iron, aluminum, chromium, arsenic

The leaching solution contains a large amount of Fe ²⁺ , Al ³⁺ , Cr ³⁺ , H ₃ AsO ₃ and must be removed in advance. Since the iron-aluminum-chromium slag is easy to adsorb and precipitate nickel-cobalt ions during the precipitation of iron-aluminum-chromium, in order to ensure the recovery rate of nickel-cobalt, a two-stage oxidation precipitation process of iron-aluminum-chromium is adopted.

Take a certain amount of the copper-replaced solution, that is, the second filtrate, put it into a beaker or reactor, start stirring, adjust the rotational speed, heat up to a set temperature of 75 °C, and start to introduce compressed air, and add 21% calcium carbonate slurry into the beaker. Or in the reactor, and start timing, a stage of oxidation to remove iron, aluminum, chromium, and arsenic to a predetermined pH value of 3.8. After the predetermined reaction time of 180 minutes, stop stirring and stop the reaction. When the temperature drops to about 65 °C, take out the slurry for filtration and washing to obtain a stage. The iron-removed liquid (third filtrate) and a section of iron-aluminum slag (third filtrate). After the solid sample is dried, the sample is divided and analyzed, and the volume of the solution is measured and analyzed for the content of base metals and precious metals.

Process parameters: temperature 75°C, time 180min, compressed air flow 130L/h, the results are shown in Table 10.

Table 10 Results of precipitation of iron, aluminum and chromium in the first stage of oxidation

After the first-stage iron removal, the liquid is carried out for the second-stage deep removal of iron, aluminum, chromium, and arsenic. The temperature is 90 ° C and the time is 2 hours. The neutralization precipitant is 10% sodium carbonate solution, and the end point is pH 4.8. The iron, aluminum and arsenic slag (fourth filter residue) is returned to the pulp for neutralization.

Process parameters: The second-stage air oxidation precipitation of iron, aluminum and chromium adopts a higher pH of 4.8, a fixed temperature of 90 ° C, a time of 180 minutes, and a compressed air flow of 130 L/h. The results are shown in Table 11.

Table 11 Results of the second-stage deep removal of iron, aluminum and chromium

Step 5. Neutralize and precipitate nickel-cobalt in stages

The nickel-cobalt in the solution is separated by the neutralization hydrolysis precipitation method, the nickel-cobalt in the solution is precipitated with sodium hydroxide solution, and the nickel-cobalt is transformed into the nickel-cobalt hydroxide slag, and at the same time, it is separated from the impurity ions in the solution. The nickel-cobalt precipitation uses a two-stage precipitation process, that is, the first stage controls a lower pH to obtain a nickel-cobalt hydroxide product with lower impurities, and the second-stage nickel-cobalt precipitation controls a higher pH to ensure complete nickel-cobalt precipitation in the solution. The nickel-cobalt hydroxide slag is returned to the residual acid for neutralization or one-stage precipitation of nickel-cobalt.

Take a certain amount of the second-stage iron, aluminum, chromium, and arsenic removal solution, add it into a beaker or reactor, start stirring, adjust the speed, and start to add 5% sodium hydroxide solution to the beaker or reactor after warming up to the set temperature. And start timing, after the predetermined pH and the predetermined reaction time, stop stirring, stop the reaction, take out the pulp for filtration and washing, the solid sample is dried and then subdivided for sampling and analysis, and the solution is measured and the volume is taken to analyze the metal content.

A stage of sodium hydroxide precipitation of nickel cobalt

Process parameters: when the concentration of sodium hydroxide solution is 5%, and the temperature is 65 ° C, 1.5L of the second-stage iron-removing aluminum-chromium solution (fourth filtrate) is added dropwise to the sodium hydroxide solution to adjust the pH of the solution, and the total reaction time is After 180 min, the endpoint pH of the control solution was 7.5. The results are shown in Table 12.

Table 12 Result of nickel-cobalt precipitation in one stage of sodium hydroxide

Second stage nickel cobalt precipitation

Process parameters; the concentration of sodium hydroxide solution is 5%, the temperature is 70 ° C, the post-precipitation solution of nickel and cobalt is 1.5L, the sodium hydroxide solution is added dropwise, the pH of the solution is adjusted, and the solution sample is taken every 30min to analyze the concentration of nickel and cobalt and the precipitation rate, The total reaction time was 180 min, and the endpoint pH of the control solution was 8.2. The results are shown in Table 13.

Table 13 Results of the second stage precipitation of nickel and cobalt

Step 6. Neutralization of tail liquid and precipitation

The solution after nickel-cobalt replacement contains a large amount of magnesium and other metal ions, and lime milk can be added to neutralize the precipitated magnesium and manganese, so that the pH of the solution is adjusted to 9.0, and compressed air is introduced for oxidation to remove the harmful element ions in the solution. Make the solution discharge standard.

Take 2.0L of the second-stage nickel-cobalt precipitation solution (i.e. tail liquid), heat it up to 50°C, introduce compressed air with a flow rate of 130L/h, and adjust the pH of the solution to 9.0 with 20% lime milk (discharge wastewater pH6～9) , the reaction time was 2.5h, and the pH of the tail liquid and the end point of the neutralization and the composition of the tail residue were investigated. The results are shown in Table 14.

Table 14 tail liquid neutralization results

Example 3

A method for treating high-chromium and high-magnesium platinum group metal ore concentrate strengthening leaching solution, which comprises the following steps:

The leachate composition includes: Au 0.003g/L, Pd 0.0047g/L, Pt 0.00095g/L, Rh 0.0014g/L, Ir0.0016g/L, Ni 2.02g/L, Cu 6.37g/L, Fe 9.62g/ L, Co 0.058g/L, As 0.0024g/L, Cr 1.16g/L, Mg 6.26g/L, Al 2.61g/L.

Step 1. Solution pre-reduction and solution residual acid neutralization

The reducing agent sodium sulfite is added to the enhanced ^leaching solution ^of platinum group metal ^ore concentrate to carry out pre-reduction reaction. Fe ²⁺ , Cr ³⁺ , and then neutralize with sodium carbonate or limestone, the residual acid content in the leaching solution is generally about 30-40g/L, adjust the pH of the pre-reduction solution to 1.7, and obtain the pre-reduced liquid ( The first filtrate) and the pre-reduced residue (the first filter residue); the reduction and neutralization reaction temperatures were both 63° C. and 63 minutes.

Step 2. Precious metal replacement

Take a certain amount of platinum and palladium flotation concentrate for enhanced leaching and pre-reduced solution, i.e. the first filtrate, add it to a beaker or reactor, start stirring, adjust the rotational speed, and start adding the reducing agent active copper powder after the temperature is raised to a set temperature of 80 °C. In the beaker or reactor, the added amount of active copper powder (wet weight) is added according to 12g/L solution, and the timing is started. After reaching the predetermined potential value of 370mv and reacting for a predetermined time of 63min, stop stirring and stop the reaction, and wait until the temperature drops to about 63 When the temperature is ℃, take out the pulp for filtration and washing, the solid sample is dried and then subdivided for sampling analysis, and the volume of the solution is measured and sampled to analyze the content of base metals and precious metals.

Process parameters: 35g of active copper powder (wet weight) was added, the replacement time was 63min, and the end point pH was 2.5.

Table 15 Result of replacing precious metal with active copper powder

Step 3. Iron powder replaces copper

Use iron powder to replace the copper ions in the solution, take a certain amount of precious metal to replace the solution, add it into a beaker or reactor, start stirring, adjust the speed, heat up to a set temperature of 85 °C, and start adding iron powder into the beaker or reactor. , and start timing. After the predetermined potential value of 100mv and the predetermined time of 100min, stop stirring and stop the reaction. When the temperature drops to about 65°C, take out the slurry for filtration and washing to obtain the iron replacement liquid (second filtrate) and the iron replacement Residue (second filter residue). After the solid sample is dried, the sample is divided and analyzed, and the volume of the solution is measured and analyzed for the content of base metals.

Process parameters: 30 g of reduced iron powder (dry weight) was added, the replacement time was 100 min, and the end point pH was 2.5. The results are shown in Table 16.

Table 16 Results of copper replacement by reduced iron powder

Step 4. Staged oxidative hydrolysis precipitation of iron, aluminum, chromium, arsenic

The leaching solution contains a large amount of Fe2+, Al3+, Cr3+, H3AsO3, which must be removed in advance. Since the iron-aluminum-chromium slag is easy to adsorb and precipitate nickel-cobalt ions during the precipitation of iron-aluminum-chromium, in order to ensure the recovery rate of nickel-cobalt, a two-stage oxidation precipitation process of iron-aluminum-chromium is adopted.

Take a certain amount of the copper-replaced solution, that is, the second filtrate, put it into a beaker or a reactor, start stirring, adjust the speed, heat up to a set temperature of 73 °C, and start to introduce compressed air, and add 20% calcium carbonate slurry into the beaker. Or in the reactor, and start timing, a stage of oxidation to remove iron, aluminum, chromium and arsenic to a predetermined pH value of 3.6, after the predetermined reaction time of 150min, stop stirring, stop the reaction, and when the temperature drops to about 63 ℃, take out the slurry, filter and wash to obtain a stage The iron-removed liquid (third filtrate) and a section of iron-aluminum slag (third filtrate). After the solid sample is dried, the sample is divided and analyzed, and the volume of the solution is measured and analyzed for the content of base metals and precious metals.

Process parameters: temperature 73°C, time 150min, compressed air flow 120L/h, the results are shown in Table 17.

Table 17 Results of precipitation of iron, aluminum and chromium in the first stage

After the first-stage iron removal, the liquid is carried out for the second-stage deep removal of iron, aluminum, chromium, and arsenic. The temperature is 80 °C, and the time is 2.5 hours. The neutralizing precipitant is 10% sodium carbonate solution, and the end point pH is 4.6-4.8. The slag, the second-stage iron, aluminum and arsenic slag (fourth filter residue) is returned to the slurry for neutralization.

Process parameters: The two-stage air oxidation precipitation of iron, aluminum and chromium adopts a relatively high pH of 4.6, a fixed temperature of 80 ° C, a time of 150 minutes, and a compressed air flow of 130 L/h. The results are shown in Table 18.

Table 18 Results of deep iron, aluminum and chromium removal in the second stage

Step 5. Staged neutralization of precipitated nickel-cobalt test

The nickel-cobalt in the solution is separated by the neutralization hydrolysis precipitation method, the nickel-cobalt in the solution is precipitated with sodium hydroxide solution, and the nickel-cobalt is transformed into the nickel-cobalt hydroxide slag, and at the same time, it is separated from the impurity ions in the solution. The nickel-cobalt precipitation uses a two-stage precipitation process, that is, the first stage controls a lower pH to obtain a nickel-cobalt hydroxide product with lower impurities, and the second-stage nickel-cobalt precipitation controls a higher pH to ensure complete nickel-cobalt precipitation in the solution. The nickel-cobalt hydroxide slag is returned to the residual acid for neutralization or one-stage precipitation of nickel-cobalt.

Take a certain amount of the second-stage iron, aluminum, chromium, and arsenic removal solution, add it into a beaker or reactor, start stirring, adjust the speed, and start to add 5% sodium hydroxide solution to the beaker or reactor after warming up to the set temperature. And start timing, after the predetermined pH and the predetermined reaction time, stop stirring, stop the reaction, take out the pulp for filtration and washing, the solid sample is dried and then subdivided for sampling and analysis, and the solution is measured and the volume is taken to analyze the metal content.

A stage of sodium hydroxide precipitation of nickel cobalt

Process parameters: when the concentration of sodium hydroxide solution is 5%, and the temperature is 62 ° C, 1.5L of the second-stage iron-removing aluminum-chromium solution (fourth filtrate) is added dropwise to the sodium hydroxide solution to adjust the pH of the solution, and the total reaction time is After 120 min, the endpoint pH of the control solution was 7.3. The results are shown in Table 19.

Table 19 results of a sodium hydroxide precipitation nickel cobalt

Two-stage sodium hydroxide precipitation of nickel and cobalt

Process parameters; the concentration of sodium hydroxide solution is 5%, the temperature is 90 ℃, the first stage of nickel and cobalt solution is 1.5L, the sodium hydroxide solution is added dropwise to adjust the pH of the solution, and the solution samples are taken every 30min to analyze the concentration of nickel and cobalt and the precipitation rate. The reaction time was 140 min, and the endpoint pH of the control solution was 8.1. The results are shown in Table 20.

Table 20 Results of the second stage precipitation of nickel and cobalt

Step 6. Neutralization of tail liquid and precipitation

The solution after nickel-cobalt replacement contains a large amount of magnesium and other metal ions. Lime milk can be added to neutralize the precipitated magnesium and manganese, so that the pH of the solution is adjusted to 8.5-9, and compressed air is introduced to oxidize the harmful element ions in the solution. Remove to make the solution discharge standard.

Take 2.0L of the second-stage nickel-cobalt precipitation solution (i.e. tail liquid), heat it up to 48°C, introduce compressed air with a flow rate of 120L/h, and adjust the pH of the solution to 8.6 with 20% lime milk (discharge wastewater pH6～9) , the reaction time was 2.3h, and the pH of the tail liquid and the end point of neutralization and the composition of tailings were investigated. The results are shown in Table 21.

Table 21 Tail liquor neutralization results

Example 4

A method for treating high-chromium and high-magnesium platinum group metal ore concentrate strengthening leaching solution, which comprises the following steps:

The leachate composition includes: Au 0.004g/L, Pd 0.0048g/L, Pt 0.00094g/L, Rh 0.0013g/L, Ir0.0016g/L, Ni 2.02g/L, Cu 6.38g/L, Fe 9.63g/ L, Co 0.058g/L, As 0.0025g/L, Cr 1.18g/L, Mg 6.30g/L, Al 2.61g/L.

Step 1. Solution pre-reduction and solution residual acid neutralization

The reducing agent sodium sulfite is added to the enhanced leaching solution of platinum group metal ore concentrate to carry out a pre-reduction reaction. The amount of sodium sulfite added is 78.78g/L solution, that is, 78.78kg/ ^m3 solution. Then use sodium carbonate or limestone for neutralization, the residual acid content in the leaching solution is generally about 30-40g/L, adjust the pH of the pre-reduction solution to 1.8, and obtain the pre-reduced liquid (first filtrate) and the pre-reduced liquid through solid-liquid separation. Residue (the first filter residue); the reduction reaction temperature was 75°C, the neutralization reaction temperature was 62°C, and the time was 62 minutes.

Step 2. Precious metal replacement

Take a certain amount of platinum and palladium flotation concentrate to strengthen the leaching and pre-reduced solution, namely the first filtrate, add it into a beaker or reactor, start stirring, adjust the speed, and start adding the reducing agent active copper powder after the temperature is raised to a set temperature of 78 °C. In the beaker or reactor, the added amount of active copper powder (wet weight) is added according to 13g/L solution, and the timing is started. After reaching the predetermined potential value of 380mv and reacting for a predetermined time for 62min, stop stirring and stop the reaction, and wait until the temperature drops to about 62 When the temperature is ℃, take out the pulp for filtration and washing, the solid sample is dried and then subdivided for sampling analysis, and the volume of the solution is measured and sampled to analyze the content of base metals and precious metals.

Process parameters: 33g of active copper powder (wet weight) was added, the replacement time was 62min, and the end point pH was 2.5.

Table 22 Result of replacing precious metal with active copper powder

Step 3. Iron powder replaces copper

Use iron powder to replace copper ions in the solution, take a certain amount of precious metal to replace the solution, add it into a beaker or reactor, start stirring, adjust the speed, and start adding iron powder to the beaker or reactor after the temperature is raised to a set temperature of 83 °C , and start timing. After the predetermined potential value is 10mv and the reaction time is 115min, stop stirring and stop the reaction. When the temperature drops to about 63°C, take out the pulp for filtration and washing to obtain the iron replacement liquid (second filtrate) and the iron replacement Residue (second filter residue). After the solid sample is dried, the sample is divided and analyzed, and the volume of the solution is measured and analyzed for the content of base metals.

Process parameters: 32 g of reduced iron powder (dry weight) was added, the replacement time was 110 min, and the endpoint pH was 2.5. The results are shown in Table 23.

Table 23 Results of copper replacement by reduced iron powder

Step 4. Staged oxidative hydrolysis precipitation of iron, aluminum, chromium, arsenic

The leaching solution contains a large amount of Fe2+, Al3+, Cr3+, H3AsO3, which must be removed in advance. Since the iron-aluminum-chromium slag is easy to adsorb and precipitate nickel-cobalt ions during the precipitation of iron-aluminum-chromium, in order to ensure the recovery rate of nickel-cobalt, a two-stage oxidation precipitation process of iron-aluminum-chromium is adopted.

Take a certain amount of the copper-replaced solution, that is, the second filtrate, put it into a beaker or reactor, start stirring, adjust the speed, heat up to a set temperature of 74°C, and start to introduce compressed air, and add 20% calcium carbonate slurry to the beaker. Or in the reactor, and start timing, a stage of oxidation to remove iron, aluminum, chromium, arsenic to a predetermined pH value of 3.7, after the predetermined reaction time of 145min, stop stirring, stop the reaction, and when the temperature drops to about 62 ℃, take out the slurry, filter and wash, get a stage The iron-removed liquid (third filtrate) and a section of iron-aluminum slag (third filtrate). After the solid sample is dried, the sample is divided and analyzed, and the volume of the solution is measured and analyzed for the content of base metals and precious metals.

Process parameters: temperature 74°C, time 2.4h, compressed air flow 118L/h, the results are shown in Table 24.

Table 24 Results of precipitation of iron, aluminum and chromium in the first stage of oxidation

After the first-stage iron removal, the liquid is carried out for the second-stage deep removal of iron, aluminum, chromium, and arsenic. The temperature is 78 ° C and the time is 2.3 hours. The neutralization precipitant adopts 10% sodium carbonate solution, and the end point pH is 4.7. The second-stage iron, aluminum and arsenic removal residue (the fourth filter residue) is returned to the pulp for neutralization.

Process parameters: The second-stage air oxidation precipitation of iron, aluminum and chromium adopts a relatively high pH of 4.7, a fixed temperature of 78°C, a time of 2.3h, and a compressed air flow of 128L/h. The results are shown in Table 25.

Table 25 Results of the second-stage deep removal of iron, aluminum and chromium

Step 5. Staged neutralization of precipitated nickel-cobalt test

The nickel-cobalt in the solution is separated by the neutralization hydrolysis precipitation method, the nickel-cobalt in the solution is precipitated with sodium hydroxide solution, and the nickel-cobalt is transformed into the nickel-cobalt hydroxide slag, and at the same time, it is separated from the impurity ions in the solution. The nickel-cobalt precipitation uses a two-stage precipitation process, that is, the first stage controls a lower pH to obtain a nickel-cobalt hydroxide product with lower impurities, and the second-stage nickel-cobalt precipitation controls a higher pH to ensure complete nickel-cobalt precipitation in the solution. The nickel-cobalt hydroxide slag is returned to the residual acid for neutralization or one-stage precipitation of nickel-cobalt.

Take a certain amount of the second-stage iron, aluminum, chromium, and arsenic removal solution, add it to a beaker or reactor, turn on stirring, adjust the speed, and heat up to a set temperature of 62 °C, start adding 5% sodium hydroxide solution to the beaker or reactor. After reaching the predetermined pH and the predetermined reaction time, stop stirring, stop the reaction, take out the pulp for filtration and washing, dry the solid sample and then subdivide the sample for analysis, and measure the volume of the solution to analyze the metal content.

A stage of sodium hydroxide precipitation of nickel cobalt

Process parameters: when the concentration of sodium hydroxide solution is 5%, and the temperature is 62 ° C, 1.5L of the second-stage iron-removing aluminum-chromium solution (fourth filtrate) is added dropwise to the sodium hydroxide solution to adjust the pH of the solution, and the total reaction time is After 128 min, the endpoint pH of the control solution was 7.2. The results are shown in Table 26.

Table 26 Result of a sodium hydroxide precipitation nickel cobalt

Second stage nickel cobalt precipitation

Process parameters; the concentration of sodium hydroxide solution is 5%, the temperature is 72 °C, the first stage of nickel and cobalt solution is 1.5L, the sodium hydroxide solution is added dropwise to adjust the pH of the solution, and the solution samples are taken every 30min to analyze the concentration of nickel and cobalt and the precipitation rate. The reaction time was 145 min, and the endpoint pH of the control solution was 8.0, respectively. The results are shown in Table 27.

Table 27 Results of the second stage precipitation of nickel and cobalt

Step 6. Neutralization of tail liquid and precipitation

The solution after nickel-cobalt replacement contains a large amount of magnesium and other metal ions. Lime milk can be added to neutralize the precipitated magnesium and manganese, so that the pH of the solution is adjusted to 8.5-9, and compressed air is introduced to oxidize the harmful element ions in the solution. Remove to make the solution discharge standard.

Take 2.0L of the second-stage nickel-cobalt precipitation solution, heat it up to 47°C, introduce compressed air at a flow rate of 100L/h, adjust the pH of the solution to 8.7 with 20% lime milk (discharge wastewater pH 6～9), the reaction time is 2.2h , to investigate the pH of the tailings neutralization endpoint and the composition of the tailings. The results are shown in Table 28.

Table 28 tail liquid neutralization results

The above descriptions are only preferred embodiments of the present invention, and do not limit the invention. It should be pointed out that for those of ordinary skill in the art, under the technical inspiration provided by the present invention, other equivalent improvements can also be made, all of which can achieve the purpose of the present invention and should be regarded as the protection scope of the present invention.

Claims (7)

1. A method for treating a platinum group metal beneficiation concentrate strengthened leaching solution, which is characterized by comprising the following steps:

(1) Adding a reducing agent sodium sulfite into the platinum group metal ore dressing concentrate enhanced leaching solution to carry out pre-reduction reaction, and adding Fe in the solution ³⁺ 、Cr ⁶⁺ Separately reduced to Fe ²⁺ 、Cr ³⁺ Then, sodium carbonate or limestone is adopted to neutralize residual acid, the pH value of the pre-reduction solution is adjusted to be 1.5-2.0, and a first filtrate and a first filter residue are obtained through solid-liquid separation; the addition amount of the sodium sulfite is 78.7-78.9 g/L solution, the temperature of the pre-reduction reaction is 60-75 ℃, and the time of the pre-reduction reaction is 60-65 min; adopting sodium carbonate or limestone to neutralize residual acid: the reaction temperature is 60-65 ℃, and the reaction time is 60-65 min;

(2) Replacing precious metals with active copper powder, adding the active copper powder into the first filtrate obtained in the step (1) to replace the precious metals, and obtaining replaced liquid and replaced slag; the reaction process for replacing the noble metal by the copper powder comprises the following steps: heating the first filtrate obtained in the step (1) to 75-85 ℃, adding active copper powder, stirring, controlling the addition amount of the active copper powder to be 12-16 g/L solution, controlling the potential value to be 350-400 mv, controlling the end point pH to be 2.5-2.8, reacting for 60-65 min, stopping stirring, and performing solid-liquid separation when the temperature is reduced to 60-65 ℃;

(3) Adding iron powder into the displaced liquid obtained in the step (2) for copper displacement reaction, and performing solid-liquid separation to obtain a second filtrate and a second filter residue; the process of replacing copper powder by iron powder is as follows: heating the displaced liquid obtained in the step (2) to 75-85 ℃, adding iron powder, wherein the adding amount of the iron powder is 10.4-16 g/L solution, controlling the potential value to be 0-100 mv, reacting for 60-120 min, stopping stirring, and performing solid-liquid separation when the temperature is reduced to 60-65 ℃;

(4) Performing a first-stage oxidation precipitation iron-aluminum-chromium-arsenic reaction on the second filtrate obtained in the step (3), performing solid-liquid separation, performing a second-stage oxidation precipitation iron-aluminum-chromium-arsenic reaction, performing a two-stage neutralization precipitation nickel-cobalt reaction, and obtaining a tail liquid and a tail slag;

(5) And (4) carrying out a manganese neutralization precipitation reaction on the tail liquid obtained in the step (4), and finally carrying out solid-liquid separation to obtain a neutralization tail liquid and neutralization tailings.

2. The method of claim 1, wherein the leachate composition comprises: au 0.003-0.004 g/L, pd.0045-0.0050 g/L, pt 0.00092-0.00098 g/L, rh 0.0012-0.0015 g/L, ir 0.0015-0.0017 g/L, ni.02-2.03 g/L, cu.36-6.39 g/L, fe.62-9.63 g/L, co 0.057-0.059 g/L, as 0.0021-0.0026 g/64 zxft 3264.13-1.20 g/82 zxft 3282.22-6.32 g/34 zxft 3234.60-3434.60-3463 g/L.

3. The method of claim 1 wherein said activated copper powder is produced by adding zinc powder to a copper sulfate solution for displacement.

4. The method according to claim 1, wherein the step (4) of the one-stage oxidation precipitation reaction process is as follows: heating the second filtrate obtained in the step (3) to 70-75 ℃, introducing compressed air with the flow rate of 100-130 l/h, adding 20-21% calcium carbonate slurry, controlling the pH value to be 3.5-3.8, reacting for 100-180 min, stopping stirring, and performing solid-liquid separation when the temperature is reduced to 60-65 ℃ to obtain third filtrate and third filter residue; and the second-stage oxidation precipitation is to heat the third filtrate to 70-90 ℃, add a sodium carbonate solution with the concentration of 10%, control the reaction time for 2-2.5 h, control the end point pH to 4.6-4.8, and obtain a fourth filtrate and a fourth filter residue through solid-liquid separation.

5. The method of claim 4, wherein the neutralization and precipitation nickel cobalt reaction process in the two stages of step (4) is: the first-stage nickel-cobalt precipitation is to heat the fourth filtrate to 60-65 ℃, dropwise add a sodium hydroxide solution, adjust the end point pH of the solution to 7.0-7.5, and perform the total reaction for 120-180 min; the second-stage nickel and cobalt precipitation is to heat the first-stage nickel and cobalt precipitation liquid to 70-90 ℃, dropwise add sodium hydroxide solution, control the end point pH of the solution to 8.0-8.2, control the total reaction time to 120-180 min, and obtain tail liquid and tailings through solid-liquid separation.

6. The method of claim 5, wherein the sodium hydroxide solution is at a concentration of 5%.

7. The method according to claim 1, wherein in the step (5), the tail liquid obtained in the step (4) is heated to 45-50 ℃, compressed air is introduced, the flow rate of the compressed air is 100-130L/h, lime milk with the concentration of 20% is added, the pH value of the tail liquid is adjusted to 8.5-9, the reaction time is 2-2.5 h, and finally, the neutralized tail liquid and the neutralized tail slag are obtained through solid-liquid separation.

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