CN102899434B - Method for synchronously extracting boron and iron in paigeite - Google Patents

Abstract

The invention provides a method for synchronously extracting boron and iron from boronite. The boronite powder and the additive composed of sodium carbonate, sodium sulfate, sodium humate, sodium fulvic acid and sodium oxalate are fully mixed and agglomerated, and the dried boronite agglomerates are made of coal as the reducing agent Carry out reduction roasting, the roasted mass is cooled and placed in a ball mill for grinding-water leaching synchronously, the slurry is separated from the solid and liquid to obtain the filtrate containing sodium metaborate and the filter residue containing metal iron powder, and the filtrate can be obtained by evaporation and crystallization. Sodium borate crystals; the filter residue can be separated by wet weak magnetic separation to obtain direct reduction metal iron powder with an iron grade greater than 90%, which is a high-quality charge for electric furnace steelmaking; the non-magnetic products of magnetic separation can be further processed to recover valuable magnesium, silicon, etc. Element. The invention has the characteristics of strong raw material adaptability, simple process flow, high production efficiency, low energy consumption, low cost, good comprehensive recovery effect of ferroboron and high added value of products, and can provide a high-efficiency utilization of boron-iron ore resources with abundant reserves in my country. Technical support, has a very broad prospects for promotion and application.

Description

A method for synchronously extracting boron and iron from boronite

technical field

The invention relates to a method for synchronously extracting boron and iron from boron ore, belonging to the fields of chemical engineering and iron and steel metallurgy.

Background technique

Boron and boron compounds have light weight, flame retardancy, heat resistance, high hardness, high strength, wear resistance and catalytic performance, and are widely used in various sectors of the national economy. Boron ore accounts for 57.88% of China's boron resources. The boron ore reserves in Liaodong alone reach 280 million tons, of which B ₂ O ₃ reserves are 21.84 million tons, which belongs to large boron deposits. Although boron-iron ore is convenient to mine, it is difficult to process and treat due to the large amount of para-existing minerals and complex structure, and it has not yet been developed and utilized on an industrial scale. Therefore, accelerating the development and utilization of boron-iron ore resources has important practical significance for alleviating the tension between the supply and demand of boron and iron resources in my country.

The key to the processing and utilization of boron ore lies in the separation of boron and iron, and the alkaline hydrolysis activity of B ₂ O ₃ is the key to determine the boron recovery rate and cost of various existing treatment processes. The carbon-soda method in the wet process is currently the mainstream process for producing borax with high-grade boron-magnesium ore as raw material. Boron-magnesium ore powder is added with soda ash solution, and the lime kiln gas (CO ₂ ) is passed into it for carbonization and filtration, and the filtrate is moderately evaporated Concentrate, cool and crystallize, and centrifuge to obtain borax; the leached slag is then subjected to magnetic separation to obtain iron concentrate to separate boron and iron. Due to the low boron content and poor activity in the boron ore raw ore, if the carbon-soda process is used directly to produce borax, high-temperature activation pretreatment is required, and the recovery rate of boron in the whole process is low, the alkali consumption is large, and the cost is high. The quality of iron ore concentrate obtained by magnetic separation is not high.

The pyrotechnic separation process mainly includes "blast furnace smelting method" and "rotary kiln direct reduction-electric furnace melting method". Boronite ore is firstly beneficiated to remove part of SiO ₂ and Al ₂ O ₃ in the original ore, and then processed into agglomerates. Blast furnace smelting or rotary kiln pre-reduction followed by electric furnace melting, the products are boron-containing pig iron and boron-rich slag. The advantage of the pyrotechnic process is that the process flow is relatively short and the equipment is simple. However, industrial experiments show that when the blast furnace smelts boron-iron ore to produce boron-containing pig iron with a boron content of about 1.0%, the production capacity of the blast furnace decreases, the coke ratio increases (about 1150kg/t), the furnace lining is severely eroded, and the product contains high sulfur. Although the content of B ₂ O ₃ in boron-rich slag can reach 12%~17% (meeting or exceeding the standard of first-grade boron-magnesium ore (B ₂ O ₃ content reaches 12%)), the B in the boron-rich slag The activity of ₂ O ₃ is low, and the chemical activity of alkaline hydrolysis is only about 50%, so it cannot be used as a raw material for the production of borax by the carbon-alkali method.

At present, there are four techniques for improving the alkaline hydrolysis activity of B ₂ O ₃ . The first one is "boron-rich slag molten state sodium treatment-pressurized water leaching borax process", by directly spraying Na ₂ CO ₃ into the molten boron-rich slag for high-temperature sodium treatment, and then pressurized water leaching, the leaching of boron The rate can reach 89%. Borax can be produced from the leachate after filtration, concentration and crystallization. However, this process requires boron-rich slag to react in a molten state, and the operating temperature is high and difficult, which is not suitable for industrialization; the second is the "slow cooling process of boron-rich slag". The activity of boron-rich slag can be improved by changing the cooling conditions of the boron-rich slag melt and avoiding a large amount of glass during the cooling process. For example, take the 13m ³ blast furnace to treat boron ore and conduct slow cooling test research on the boron-rich slag obtained from smelting and separation as an example. The controlled cooling rate in the range of 900 °C should be less than 2 °C/min), and the activity of boron-rich slag can be increased from 40.05% to 83.72%. However, it is more difficult to implement slow cooling in industry, which restricts the application of "fire method" technology, and has not achieved long-term stable industrial production so far; Roasting process". The reactivity of boron-rich slag/boronite can be improved by using sodium roasting pretreatment. Patent "method of activating maficite" (application number: 200710157450.1) mix sodium carbonate with maficite powder in a certain mass percentage in advance (mass ratio Na ₂ O:B ₂ O ₃ =0.6~2.0 : 1), oxidize and roast at high temperature (750°C~1000°C) to convert B ₂ O ₃ in maficite into water-soluble sodium borate, with a reactivity of 90%~96%, and then grind the material Sodium borate or borax can be obtained after finely immersing in water, and the filtered sodium borate solution is evaporated, cooled, crystallized or carbonated. On the basis of sodium roasting activation pretreatment, activated carbon was added to carry out magnetized sodium roasting on the boron concentrate, and the boron concentrate was fully mixed with 20% activated carbon and 26.6% sodium carbonate according to the mass percentage, and the mixture was put into a corundum crucible and placed in a horse. Roasting at 950°C for 2 hours in a Furnace, the activity of the boron concentrate after roasting can reach 88.22%, and the magnetic properties are significantly enhanced. After the roasted sample is extracted by hydrothermal leaching, the waste residue produced is mainly forsterite and magnetite. The magnetite can be separated in the second magnetic separation, and the forsterite can be used as a raw material for glass-ceramics. The advantage of this process is that during the roasting process, the reactivity of B ₂ O ₃ can be increased, and the magnetic properties of the filter residue can be enhanced. After the filter residue is magnetically separated, magnetite concentrate can be obtained, which improves the slag (boron mud) to a certain extent. Comprehensive utilization value, but after roasting, the sample is generally subjected to pressurized hydrothermal leaching (100 ° C ~ 180 ° C), the material handling capacity is large, the efficiency is low, and the cost is high, and the product obtained after the filter residue is magnetically separated is magnetite concentrate. The added value is not high.

In addition, "A Process for Calcifying and Roasting Boron-rich Slag" (application number: 201010141311.1) improves its reactivity by calcifying and roasting boron-rich slag, and the roasted product can be used as a raw material for the production of carbon-soda borax. The method uses limestone, slaked lime or lime as additives, and under normal pressure and 800°C~1100°C, the particle size is 80 mesh to 350 mesh, containing 10%~20%B ₂ O ₃ , 30%~55%MgO, 2 The boron-rich slag with %~15%CaO is calcified and roasted for 0.5h~6h, and then the carbonization reaction is carried out at 120℃~150℃ to prepare borax. The normal pressure alkaline hydrolysis activity of the boron-rich slag treated with calcification and roasting is 85%~92%, the carbonization rate is 82%~90%, and the boron yield is 78%~86%. The advantage of this process is that it uses cheap limestone or lime as an additive to calcify and roast the boron-rich slag with a chemical reactivity lower than 50%, which increases the activity by 35% to 45%. It can be used as a raw material for carbon-soda borax production. The problems of complex technological process and high cost still exist when carbon-soda method is used to prepare borax.

To sum up, most of the existing treatment processes of boron-iron ore cannot realize the synchronous and efficient separation of boron and iron to obtain high value-added products. For example: the blast furnace method realizes the reduction of iron oxides and the separation of slag and iron by agglomerating boron ore and then smelting in the blast furnace. The products are boron-containing pig iron and boron-rich slag. Slow cooling, calcification and roasting, molten sodium) provide highly active boron-containing raw materials for the carbon-alkali method or directly pressurized water leaching to produce borax. The technical route of "iron first and then boron" in the blast furnace method must be treated by the two-step method of blast furnace reduction and boron-rich slag activation. The process is long, high in cost, and the comprehensive recovery rate of boron is low (<85%). The sodium roasting process can activate boron and increase the magnetism of the filter residue during the roasting process. However, after the roasting, the whole sample is subjected to pressurized hydrothermal leaching, which has a large amount of material handling and low efficiency, and the filter residue obtained after magnetic separation is only As a raw material for ironmaking, magnetite concentrate has low added value.

Contents of the invention

The invention aims to provide a method for synchronously extracting boron and iron from boron-iron ore with strong raw material adaptability, simple process flow, high production efficiency, low energy consumption, low cost and high comprehensive recovery rate of boron and iron.

A method for synchronously extracting boron and iron from boron ore in the present invention is to crush boron ore to -3 mm boron ore powder, wherein the -1 mm particle size of boron ferrite ore powder accounts for more than Equal to 60%; Add additives accounting for 15%~30% of the mass percentage of boron iron ore powder, mix, agglomerate, dry, and then use coal as a reducing agent for reduction roasting, the reduction product is crushed, ground and leached, solid-liquid Separation, the filter residue is sorted by wet weak magnetic separation to obtain direct reduction metal iron powder, and the filtrate is evaporated and crystallized to obtain sodium metaborate.

The invention discloses a method for synchronously extracting boron and iron from boron iron ore. The additive is a mixture of sodium carbonate, sodium sulfate, sodium humate, sodium fulvic acid and sodium oxalate; the particle size of the additive is 0.05-0.5mm ; The mass percent of each component in the additive is:

Sodium carbonate 50%~85%;

Sodium sulfate 5%~25%;

Sodium humate 1%~20%;

Sodium fulvic acid 1%~3%;

Sodium oxalate 1%~20%.

The invention discloses a method for synchronously extracting boron and iron from boron-iron ore. The reduction roasting temperature is 1000 DEG C to 1100 DEG C, and the reduction roasting time is 60 min to 90 min.

The invention discloses a method for synchronously extracting boron and iron from boron ore, and the reduction product is used for grinding, leaching, and solid-liquid separation.

The invention discloses a method for synchronously extracting boron and iron from boron-iron ore. The ore grinding and leaching is to perform wet ball milling in a ball mill to synchronously leach sodium metaborate.

The invention discloses a method for synchronously extracting boron and iron from boron ore. The ball milling medium of the wet ball mill is water, and the mixture of the reduction product and water constitutes the ball milling material, and the mass percent concentration of the ball milling material is 50% to 70%. , the mass ratio of balls to milling materials is (7~10):1, the wet ball milling time is not less than 20min, and the pulp is obtained after ball milling.

The invention discloses a method for synchronously extracting boron and iron from boronite ore. After the solid-liquid separation of the ore pulp, the filtrate is an aqueous solution containing sodium metaborate, and the filtrate is evaporated and crystallized to obtain sodium metaborate crystals; the filter residue is metal-containing Iron powder filter cake and filter residue are separated by slurry mixing and wet weak magnetic separation to obtain metal iron powder.

Mechanism of the present invention is briefly described below:

During the direct roasting process of boronite ore, because Na ₂ O in the additive can chemically react with B ₂ O ₃ in the ore to form sodium metaborate with low melting point, which activates the boron in boronite ore and destroys the original ore. At the same time, the low melting point promotes the aggregation and growth of metallic iron grains; in addition, Na ⁺ ions with a smaller ionic radius can cause lattice distortion of iron oxides, catalyze the reduction of iron oxides, and provide Create favorable conditions for the separation of iron and boron. In addition, the H ₂ and CO produced by the cracking of humic acid, fulvic acid and oxalic acid in the additive can promote the reduction of iron oxides and increase the reduction rate.

The main reactions that occur during the reduction roasting process are:

(Mg,Fe) ₂ Fe[BO ₃ ]O ₂ +Na ₂ O+CO/H ₂ ↑→NaBO ₂ +Fe+MgO+CO ₂ /H ₂ O↑

Fe ₃ O ₄ +CO/H ₂ ↑→Fe+CO ₂ /H ₂ O↑

3MgO·2SiO ₂ ·2H ₂ O→2MgO·SiO ₂ (forsterite)+MgO·SiO ₂ (amorphous)+H ₂ O↑

MgO·SiO ₂ (amorphous)+MgO→2MgO·SiO ₂ (forsterite)

The present invention combines iron ore coal-based direct reduction technology with grinding-water leaching-magnetic separation and is applied to the comprehensive utilization of boron-iron ore resources, which not only solves the disadvantage of insignificant separation effect of boron and iron in existing beneficiation technology, but also enables The boron iron ore resource has been fully utilized to the greatest extent, adding high-efficiency additives for reduction roasting to reduce iron oxides to metallic iron and at the same _time transform the boron component into soluble sodium metaborate, which improves the reactivity of _B2O3 , thus realizing Grinding-water leaching is used to extract boron simultaneously, and the filter residue is subjected to magnetic separation to obtain metallic iron powder. The recovery rate of boron in the whole process is more than 85%, and the obtained magnetic product is direct reduction metal iron powder with an iron grade of more than 90%, which is a high-quality charge for electric furnace steelmaking. The recovery rate of iron magnetic separation is more than 90%. The non-magnetic products of magnetic separation can be further processed to recover valuable components such as magnesium and silicon.

The advantages of the present invention are:

1. Grinding and water leaching of the reduced product are carried out simultaneously, and the process operation is simple. The new process saves the high-energy-consuming processes such as reduction-melting of blast furnace, electric furnace or submerged arc furnace. After reduction and roasting of boron ore, sodium metaborate and metal iron powder can be directly prepared through grinding-water leaching-magnetic separation. Raw material adaptability Strong, boron iron ore and its secondary product of beneficiation, boron-containing iron concentrate, can all be applied to this process, with short process flow, low energy consumption, high production efficiency and low cost.

2. Wet-type weak magnetic separation is used for leaching slag after pulping, and the iron recovery effect is good. The obtained metal iron powder has low impurity content and high iron grade. It is a high-quality raw material for electric furnace steelmaking, so the added value of iron products is high; magnetic separation tail The ore can be used as a magnesium-containing raw material to produce refractory materials or magnesium compounds, and valuable elements such as boron, iron, and magnesium can be recycled, and the comprehensive utilization rate is high.

In summary, the present invention has the characteristics of simple process flow, high production efficiency, low energy consumption, low cost, strong raw material adaptability, high comprehensive recovery rate of ferroboron, good product quality and high added value. The invention provides a new effective way for the high-efficiency development and utilization of boron-iron ore resources with abundant reserves in my country, and has very broad promotion and application prospects.

Description of drawings

Accompanying drawing 1 is process flow diagram of the present invention.

Detailed ways

The main chemical composition of the boronite used is shown in Table 1. The boronite is pre-crushed and ground to -3mm boronite powder, wherein the boronite powder with a particle size of -1mm accounts for more than Equal to 60%.

Table 1. The main chemical composition of boronite/%

[Comparative example]

Comparative Example 1: After agglomerating and drying boronite powder, use lignite as reducing agent, reduce and roast at 1000°C for 90 minutes, place the reduced product in a ball mill with 50% pulp mass percentage concentration, grind balls The mass ratio to the ball mill material was 10:1 for grinding-water leaching for 40 minutes. After the pulp was filtered, the boron leaching rate was 1.62%. The filter residue was sorted by wet weak magnetic separation. The iron grade in the obtained iron concentrate was 83.32%. The recovery rate was 86.75%.

Comparative Example 2: After agglomerating and drying boronite powder, using lignite as reducing agent, roasting at 1100°C for 60 minutes, placing the reduced product in a ball mill with 50% pulp concentration, grinding balls and The mass ratio of the ball milling material was 10:1 for grinding-water leaching for 55 minutes. After the slurry was filtered, the boron leaching rate was 1.93%. The filter residue was sorted by wet weak magnetic separation. The recovery rate is 92.06%.

Comparative example 3: According to the main conditions provided in the application of the patent "Method for activating boronite ore" (application number: 200710157450.1), fully mix boronite powder with sodium carbonate accounting for 30% of its mass fraction, and make After the blocks are dried, they are oxidized and roasted at 1000°C for 60 minutes, and the roasted product is placed in a ball mill for grinding-water immersion for 40 minutes with a mass percentage concentration of 50% ore pulp and a mass ratio of balls to ball milled materials of 10:1. After the pulp was filtered, the boron leaching rate was 54.2%, and the filter residue was separated by wet weak magnetic separation method. The iron grade in the obtained iron concentrate was 51.49%, and the recovery rate of ferromagnetic separation was 73.56%.

[specific example]

Embodiment 1: 85% sodium carbonate, 5% sodium sulfate, 1% sodium fulvic acid, 4% sodium humate, and 5% sodium oxalate are mixed and formulated as an additive, and boronite powder and its mass fraction are 15% After the above additives are fully mixed, agglomerated, and dried, lignite is used as the reducing agent, and the reduction roasting is carried out at 1000°C for 60 minutes. The mass ratio of the materials was 10:1 for grinding-water leaching for 30 minutes. After the slurry was filtered, the boron leaching rate was 85.54%. The filter residue was sorted by wet weak magnetic separation. The iron grade in the obtained iron concentrate was 86.57%. The rate is 90.81%.

Embodiment 2: 70% sodium carbonate, 20% sodium sulfate, 2% sodium fulvic acid, 4% sodium humate, and 4% sodium oxalate are mixed and formulated as additives, and boronite powder and its mass fraction are 20% After the above additives are mixed, agglomerated, and dried, anthracite is used as a reducing agent, and the reduction roasting is carried out at a temperature of 1100°C for 60 minutes. The mass ratio was 10:1 for grinding-water leaching for 30 minutes. After the slurry was filtered, the boron leaching rate was 87.80%. The filter residue was sorted by wet weak magnetic separation method. 93.67%.

Embodiment 3: 50% sodium carbonate, 25% sodium sulfate, 3% sodium fulvic acid, 10% sodium humate, and 12% sodium oxalate are mixed and formulated as an additive, and boronite powder and its mass fraction are 30% After the above-mentioned additives are mixed, agglomerated and dried, lignite is used as reducing agent, reduced and roasted at 1100°C for 60 minutes, and the reduced product is placed in a ball mill with 60% pulp concentration, balls and ball milled materials The mass ratio is 8:1 for immersion in water for 20 minutes. After the slurry is filtered, the boron leaching rate is 89.21%. The filter residue is sorted by wet weak magnetic separation method. The iron grade in the obtained iron concentrate is 92.46%, and the recovery rate of ferromagnetic separation is 93.85%. .

Embodiment 4: 70% sodium carbonate, 5% sodium sulfate, 2% sodium fulvic acid, 3% sodium humate, and 20% sodium oxalate are mixed and formulated as an additive, and boronite powder and its mass fraction are 20% After the above-mentioned additives are mixed, agglomerated and dried, lignite is used as reducing agent, reduced and roasted at 1100°C for 90 minutes, and the reduced product is placed in a ball mill with a concentration of 60% pulp mass, balls and ball milled materials The mass ratio was 8:1 for grinding-water leaching for 20 minutes. After the pulp was filtered, the boron leaching rate was 90.32%. The filter residue was sorted by wet weak magnetic separation method. 95.79%.

Embodiment 5: 70% sodium carbonate, 10% sodium sulfate, 2% sodium fulvic acid, 13% sodium humate, and 5% sodium oxalate are mixed and formulated as an additive, and boronite powder and its mass fraction are 20% After the above additives are mixed, agglomerated, and dried, lignite is used as a reducing agent, and the reduction roasting is carried out at a temperature of 1100°C for 75 minutes. The mass ratio was 7:1 for grinding-water leaching for 40 minutes. After the pulp was filtered, the boron leaching rate was 90.73%. The filter residue was sorted by wet weak magnetic separation method. 95.98%.

Embodiment 6: 52% sodium carbonate, 10% sodium sulfate, 2% sodium fulvic acid, 20% sodium humate, and 10% sodium oxalate are mixed and formulated as additives, and boronite powder and its mass fraction are 20% After the above additives are mixed, agglomerated, and dried, bituminous coal is used as a reducing agent, and they are reduced and roasted at a temperature of 1100°C for 90 minutes. The mass ratio was 7:1 for grinding-water leaching for 40 minutes. After the slurry was filtered, the boron leaching rate was 91.68%. The filter residue was sorted by wet weak magnetic separation method. 96.43%.

As can be known from the detection results of the above examples and comparative examples, adopting the method of the present invention not only can extract boron and iron synchronously from boronite ore, but also the boron recovery rate of the whole process reaches more than 85%, which is the same as that of comparative example 1 and comparative example 2. More than 40 times of the middle boron recovery rate, compared with the boron recovery rate in Comparative Example 3, the increase rate is greater than 30%; the gained magnetic product is the direct reduction metal iron powder with an iron grade greater than 90%, and the magnetic separation recovery rate of iron is greater than 90%; The magnetically separated iron concentrates obtained in Comparative Example 1 and Comparative Example 2 cannot be directly used for electric furnace steelmaking due to low iron grades, and the magnetically separated iron concentrates obtained in Comparative Example 3 can only be used as ironmaking raw materials.

Claims (4)

1. a method for simultaneous extraction boron and iron from paigeite, is characterized in that: the paigeite powder of paigeite is crushed to-3mm, and the paigeite powder of wherein-1mm grade accounts for paigeite powder mass percent and is more than or equal to 60%; Add the additive that accounts for paigeite powder mass percent 15% ~ 30%, mix, agglomeration, oven dry, then carry out reducing roasting take coal as reductive agent, reduzate leaches through broken, ore grinding, solid-liquid separation, filter residue adopts the sorting of wet type low intensity magnetic separation method to obtain direct-reduction metal iron powder, and filtrate obtains sodium metaborate through evaporation, crystallization; It is in ball mill, to carry out wet ball-milling leaching simultaneously sodium metaborate that described ore grinding leaches;

Described additive is the mixture of sodium carbonate, sodium sulfate, natrium humate, SODLUM FULVATE, sodium oxalate; The granularity of additive is 0.05-0.5mm; In described additive, the mass percent of each component is:

Sodium carbonate 50% ~ 85%;

Sodium sulfate 5% ~ 25%;

Natrium humate 1% ~ 20%;

SODLUM FULVATE 1% ~ 3%;

Sodium oxalate 1% ~ 20%.

According to claim 1 a kind of from paigeite the method for simultaneous extraction boron and iron, it is characterized in that: described reducing roasting temperature is 1000 ℃ ~ 1100 ℃, reducing roasting time 60min ~ 90min.

According to claim 2 a kind of from paigeite the method for simultaneous extraction boron and iron, it is characterized in that: the ball-milling medium of described wet ball-milling is water, the mixture of reduzate and water forms ball milling material, the mass percentage concentration of ball milling material is 50% ~ 70%, the mass ratio of abrading-ball and ball milling material is (7 ~ 10): 1, the wet ball-milling time is no less than 20min, obtains ore pulp after ball milling.

According to claim 3 a kind of from paigeite the method for simultaneous extraction boron and iron, it is characterized in that: after described solid-liquid separation on ore pulp, filtrate is the aqueous solution containing sodium metaborate, and filtrate makes sodium metaborate crystal through evaporation, crystallization; Filter residue is containing metal iron powder filter cake, filter residue through sizing mixing, wet type low intensity magnetic separation separates and obtains metal iron powder.

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