CN115976340A - Device and method for separating antimony from crude arsenic by vacuum distillation - Google Patents

Abstract

The invention discloses a device and a method for separating antimony from crude arsenic by vacuum distillation, and belongs to the technical field of crude arsenic purification. The device provided by the invention comprises a reactor cover, a temperature measuring device, a cooling device, a condensing tower, a heating device, a connecting flange, a vacuum tank body, a charging crucible, a vacuumizing device and a control system. The invention also provides a method for separating antimony from crude arsenic by vacuum distillation by using the device, which adopts a technical route of realizing vacuum distillation fractional condensation by using an adjustable multistage condensation tower, wherein the inter-stage distance can be adjusted by changing the position of a nut, the volatilized antimony vapor and part of arsenic vapor are condensed on a condensing sheet with higher temperature by utilizing the difference between the saturated vapor pressure and the condensation temperature of arsenic, antimony vapor and other low-boiling-point substances and the position of a condensing sheet is adjusted, the low-boiling-point substances are condensed on a collecting device at the upper part of a furnace body, and arsenic with lower antimony content is collected by the condensing sheet in a medium-low temperature region, so that the efficient separation of the arsenic and the antimony is realized.

Description

A device and method for vacuum distillation and separation of antimony from crude arsenic

technical field

The invention relates to the technical field of crude arsenic purification; in particular, it relates to a device and method for vacuum distillation and separation of antimony from crude arsenic.

Background technique

Arsenic has excellent physical and chemical properties. As a metal additive, it can improve the properties of metal materials; arsenic can be combined with a series of metals to form alloy materials, such as arsenic-lead alloy and arsenic-copper alloy. Arsenic-lead alloy is mainly used in the production of lead batteries and military lead bullets , arsenic-copper alloys are mainly used in the production of supporting screw rods for train combustion chambers and parts in high-temperature reducing atmospheres. Semiconductor material is one of the most important applications of arsenic. It is mainly used in the synthesis of gallium arsenide and indium arsenide. It can also be used as a doping element for semiconductor materials germanium and silicon. Doping arsenic will greatly improve the conductivity of semiconductors. As the core material of the second-generation semiconductor, arsenic has become a key material supporting high-tech development and new product development. Arsenic also has medical value, and studies have proved that arsenic plays an important role in the field of anti-cancer. Arsenic is also an important raw material for the preparation of herbicides, insecticides, preservatives, pigments and other materials. With the development of the arsenic industry, arsenic plays an increasingly important role in the fields of metallurgy, materials, chemical industry and medical treatment.

Most of the arsenic is associated with tin, lead, zinc, copper, gold and other non-ferrous metal ores. There are very few independent arsenic deposits. The recovery of mineral resources in my country has far exceeded the current demand for arsenic. Therefore, there are generally no arsenic deposits alone. Re-mining mainly extracts and utilizes arsenic from high-arsenic dust and arsenic sulfide slag with high arsenic content in the secondary resources of non-ferrous smelting. Due to the complex composition of raw materials, especially antimony, which is the main group impurity, enters the finished product during the production process. Higher levels lead to low-grade industrial arsenic produced, making it difficult to sell and low in price. However, the supply of high-grade arsenic is in short supply and the price is high. The development of effective equipment and methods for separating antimony from crude arsenic is conducive to promoting the development of harmless and resourceful disposal of arsenic-containing materials, and the production of high-grade arsenic will create good social and economic benefits.

At present, the methods for purifying arsenic and separating antimony mainly include chemical purification and physical purification. The chemical purification method obtains high-grade arsenic by chlorinating and rectifying the arsenic, and then reducing it with hydrogen. CN103184354A discloses a method for preparing high-purity arsenic. Crude arsenic is obtained through four steps of vacuum distillation-chlorine chlorination-rectification purification-hydrogen reduction. This method is the mainstream method for preparing high-grade arsenic, but it has a long process, high requirements for equipment, safety risks in the production process, high production cost, and unstable product quality. The physical purification method is based on the different saturated vapor pressures of the elements in crude arsenic at different temperatures, or the method of adding alloys and impurity elements to form refractory compounds. Under certain temperature and system pressure conditions, arsenic elements with high saturated vapor pressures are preferentially volatilized , Condensed, thus separated from other impurity elements. CN101054168A discloses a production method of high-purity arsenic. First, arsenic and lead are heated in a crucible at a ratio of 1:1.5 to 4 to prepare an arsenic-lead alloy. The crucible is placed in a vacuum tank and connected to a conical condenser. Vacuum heating, arsenic condenses on the condenser, impurity elements remain in the residue to achieve separation, and high-grade arsenic is obtained. The method has stable quality and low cost, but the labor intensity of the production process is high. CN112226633A discloses a device capable of reducing antimony content in industrial arsenic and its production method. The device consists of a heating furnace, a vacuum tank body, a charging crucible, a refractory material layer, a conical condenser, a condensing shunt sieve plate, and a vacuum system ; The structure of the device is relatively simple, the processing flow is relatively short, but the process is difficult to control, and the requirements for raw materials are relatively high.

Contents of the invention

Aiming at the existing problems of crude arsenic purification, the present invention provides a device for vacuum distillation and separation of antimony from crude arsenic; a certain temperature gradient is formed in the device, and arsenic and antimony vapors are condensed in different positions by stages according to the difference in saturated vapor pressure and condensation temperature Condensation to realize high-efficiency separation; the present invention is realized through the following technical solutions:

A device for vacuum distillation and separation of antimony from crude arsenic, comprising a reactor cover 1, a temperature measuring device 2, a cooling device 3, a condensation tower 4, a heating device 5, a connecting flange 6, a vacuum tank body 7, and a charging crucible 8 , vacuuming device 9 and control system 10; the charging crucible 8 and the heating device 5 are placed at the bottom of the vacuum tank body 7, and the heating device 5 heats the charging crucible 8 around, and the charging crucible 8 and the heating device 5 are placed above Multi-stage condensing tower 4, multi-stage condensing tower 4 is equipped with a plurality of condensing fins and a central screw, the condensing fins are fixed on the central screw by nuts, and the position of the condensing fins is adjusted by adjusting the nuts, the condensing fins have airflow holes, adjacent The airflow holes on the two condensing sheets are relatively arranged, and the condensing sheet is provided with a fixed temperature measuring device 2; above the condensation tower 4 is a reactor cover 1, and the reactor cover 1 is connected with a vacuum device 9, and the vacuum device 9 passes through the flange Connected with the vacuum tank, the reactor cover 1 is equipped with a cooling device 3, and the low boiling point impurities and tail gas are collected on the reactor cover; the whole device is connected with the control system 10.

The condensing tower 4 of the present invention is cylindrical, and the condensing fins are fixed by gaskets.

The condensing tower 4 of the present invention realizes multi-stage condensation by changing the number of condensing fins, and achieves the purpose of controllable and adjustable condensation stages; by changing the positions of the nuts and washers used to fix the condensing fins, the precise and controllable stage spacing is realized, To achieve the goal that the stage spacing can be relatively accurately adjusted according to the desired experimental effect; by changing the position of the nut and the washer, the condensation fins can move on the screw, so that the height of the condensation fins at each level relative to the heating surface can be accurately controlled, reaching the condensation temperature zone The purpose of relatively precise regulation can be carried out according to the desired experimental effect.

Preferably, the vacuum tank body 7 and the heating device 5 on one side of the charging crucible 8 according to the present invention are provided with a hermetic door, which is convenient for taking out and putting into the charging crucible 8 .

Preferably, the height of the condensation tower 4 of the present invention is 26.0 cm, the thickness of the condensation sheet is 5 mm, the thickness of the nut is 10.5 mm, and the thickness of the gasket is 2.5 mm.

Preferably, in the present invention, raw materials are added to the charging crucible 8 in the vacuum tank body 7, the vacuum device 9 and the cooling device 3 are turned on, and the steam is condensed in the condensation tower 4, and the condensation temperature zone is from the set temperature to 80°C Full coverage, by changing the number of stages, positions and spacing of the condensing plates, the volatilized antimony vapor and part of the arsenic vapor are condensed on the condensing plate with a higher temperature, and the low boiling point impurities and exhaust gas are collected on the reactor cover on the upper part of the furnace body; Arsenic with low antimony content was collected in the condensate pan in the middle and low temperature area.

Preferably, the raw material of the present invention is crude arsenic containing 0.5% to 2% antimony and a purity of 96% to 98%;

Preferably, the pressure inside the vacuum tank 7 of the present invention is 1-10000 Pa, the distillation temperature is 400-650° C., and the distillation time is 1-7 hours.

Beneficial effects of the present invention:

(1) There is no arsenic-containing waste gas and waste water produced in the production process of this method, which is safe and pollution-free; the furnace structure is reasonable, and the charging crucible and heating device of the device are inside the vacuum tank, and the heat transfer efficiency is high, so that the crude arsenic is melted quickly and the production The efficiency is greatly improved and the production cost is reduced; at the same time, the external heating method of the traditional vacuum furnace is changed, and only the surrounding of the crucible is heated, which improves the heating efficiency and has sufficient internal space.

(2) The device of the present invention can directly take out the charging crucible, which improves the difficult problem of taking and discharging materials in traditional vacuum furnaces; the top is provided with a cooling device 3, which can control the reactor cover temperature to be lower than 80 degrees, so that low-boiling impurities and The tail gas is collected on the reactor hood.

(3) The condensing zone of the device described in the present invention is a multi-stage condensation tower, which can realize multi-stage condensation by adjusting the number of condensing fins; can realize precise control of the stage spacing by adjusting the spacing of the condensing fins; can adjust the condensation fins on the central screw position to realize the control of the condensing temperature zone; the above-mentioned three coordinate regulation, so as to obtain the needs of different stages, different strokes and different temperature zones of the mixed vapor in the vacuum distillation process, and it is easy to realize the fine control of the separation effect; the condensing tower is circular Cylindrical, the condensed steam will not volatilize to the vacuum furnace wall, which is convenient for cleaning.

(4) The top of the device of the present invention is provided with a vacuum device to realize dual control of air pressure and temperature in the vacuum furnace, and better control of condensation conditions.

(5) The technological process of the present invention is short, thick arsenic is condensed through vacuum distillation classification, after vacuum gasification separation and purification, can obtain the arsenic that contains antimony not higher than 0.04%, the product quality is high, and impurity antimony element separation effect is good, required The equipment is simple, the purification cost is low, the recovery rate is high, and the working environment is safe and friendly.

(6) The method has wide raw material adaptability and wide operable conditions, and can find raw materials with different amounts of arsenic and antimony, and optimal condensation temperature zones under different conditions.

Description of drawings

Fig. 1 is a schematic diagram of the device of the present invention.

Fig. 2 is a structural schematic diagram of the condensation pan of the present invention.

Fig. 3 is a schematic diagram of the connection of the condensation pan of the present invention.

In the figure: 1-reactor cover, 2-temperature measuring device, 3-cooling device, 4-condensing tower, 5-heating device, 6-connecting flange, 7-vacuum tank, 8-charging crucible, 9- Vacuum device; 10-control system.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited to the content described.

Example 1

A device for vacuum distillation and separation of antimony from crude arsenic, comprising a reactor cover 1, a temperature measuring device 2, a cooling device 3, a condensation tower 4, a heating device 5, a connecting flange 6, a vacuum tank body 7, and a charging crucible 8 , a vacuuming device 9 and a control system 10; the charging crucible 8 and the heating device 5 are placed at the bottom of the vacuum tank body 7, and the heating device 5 heats the charging crucible 8 around to improve heating efficiency and avoid traditional equipment from affecting the entire furnace. The heat loss caused by body heating is more; the condensing tower 4 is placed above the charging crucible 8 and the heating device 5. The condensing tower 4 is cylindrical and has a height of 26.0 cm. The condensing tower 4 is built with a central screw, and the condensing sheet is covered On the central screw, the two sides are fixed with nuts or washers. There are airflow holes on the condensation sheet, and the airflow holes of two adjacent condensation sheets are placed opposite each other. A fixed temperature measuring device 2 is installed outside the condensation tower 4; The stroke is determined by the number of condensation fins, and the temperature and spacing of the condensation zones at all levels are determined by the position of the condensation fins, which are fixed by nuts and washers. The mixed vapor is condensed in the condensation tower, the condensation temperature area covers a wide range, the condensation temperature gradient is obvious, and the condensation interval is flexible and controllable. The collected materials can more truly reflect the condensation conditions corresponding to the condensed phase composition here; above the condensation tower 4 is Reactor cover 1, the reactor cover 1 is connected with the vacuum device 9, the vacuum device 9 is connected with the vacuum tank through the flange, the reactor cover 1 is provided with a cooling device 3, and the low boiling point impurities and tail gas are placed on the reactor cover Collect; the whole device is connected with the control system 10; the vacuum tank body 7 on one side of the charging crucible 8 and the heating device 5 are provided with a sealed door, which is convenient for taking out and putting into the charging crucible 8.

Example 2

Process 300g of block-shaped crude arsenic containing 96.88% arsenic and 0.32% antimony to a small block with a diameter of less than 1 cm, put it into a charging crucible 8, and put the charging crucible 8 into a vacuum tank 7 with a heating device 5 In the process, a condensing tower 4 is placed on the upper part of the charging crucible 8, and a condensing sheet is arranged and fixed every 4.7 cm in the condensing tower to form 5 equidistant condensing intervals. After the condensing tower 4 is installed, the reactor cover 1 is installed and connected to a vacuum pump. Device 9, the control pressure is 1Pa, the distillation temperature is 420-470°C, and the distillation time is 3h. After the pressure is stable, the temperature is raised at a rate of 10°C/min, and the cooling water switch is turned on at the same time.

During the heating process, the arsenic and antimony in the charging crucible 8 evaporate to form steam, and after passing through the condensation tower 4, the volatilized antimony vapor and part of the arsenic vapor are condensed on the higher temperature condensation sheet, and the low boiling matter is collected in the upper part of the furnace body. Condensate, collect arsenic with low antimony content in the middle and low temperature area, and the condensed products are mainly concentrated in the temperature range of 170-80 °C; after the reaction is completed, the temperature is lowered to below 100 °C, the cooling water is turned off, the pump is stopped, and the materials are collected. During the experiment, the measured condensation temperature zones were 352.8°C in zone I, 318.7°C in zone II, 220°C in zone III, 169.9°C in zone IV, and 134.4°C in zone V.

51.2g was collected in zone Ⅰ, 11.4g in zone Ⅱ, 19.4g in zone Ⅲ, 135.7g in zone Ⅳ, 53.3g in zone Ⅴ, 23.7g in the reactor cover, 0.9g in the crucible, and the volatilization rate reached 98.23%. The yield is 69.43%; the obtained arsenic is detected with reference to the non-ferrous metal industry standard TS/T68-2014 of the People's Republic of China by using an inductively coupled plasma mass spectrometer (ICP-MS). %.

Example 3

Treat 300 g of block-shaped crude arsenic containing 96.72% arsenic and 0.81% antimony to a small block with a diameter of less than 1 cm, put it into a charging crucible 8, and put the charging crucible 8 into a vacuum tank 7 with a heating device 5 In the process, a condensing tower 4 is placed on the upper part of the charging crucible 8, and a condensing sheet is set and fixed every 4.7cm in the condensing tower to form 5 equidistant condensing intervals, which correspond to the temperature measuring points. After the condensing tower 4 is installed, install the reaction The cover 1 is connected to the vacuum device 9, the control pressure is 5000Pa, the distillation temperature is 480-520°C, and the distillation time is 6h. After the pressure is stable, the temperature is raised at a rate of 10°C/min, and the cooling water switch is turned on at the same time.

During the heating process, the arsenic and antimony in the charging crucible 8 evaporate to form steam, and pass through the condensation tower 4, so that the volatilized antimony vapor and part of the arsenic vapor are condensed on the higher-temperature condensation sheet, and the low-boilers are condensed in the upper part of the furnace. , Collect arsenic with low antimony content in the middle and low temperature area, and the condensed products are mainly concentrated in the temperature range of 230-80 °C; after the reaction is completed, the temperature is lowered to below 100 °C, the cooling water is turned off, the pump is stopped, and the materials are collected. During the experiment, the corresponding condensation temperature zones of each condensing sheet were 432.9°C in zone I, 391.0°C in zone II, 278.2°C in zone III, 229.5°C in zone IV, and 174.1°C in zone V.

Collect 0.7g in zone Ⅰ, 5.7g in zone Ⅱ, 17g in zone Ⅲ, 71.2g in zone Ⅳ, 130.3g in zone Ⅴ, 66.5g in the reactor hood, and 0.5g in the crucible. The volatilization rate reaches 97.13%. The yield is 72.83%; the obtained arsenic is detected with reference to the non-ferrous metal industry standard TS/T68-2014 of the People's Republic of China by using an inductively coupled plasma mass spectrometer (ICP-MS). .

Example 4

Process 300g of block-shaped crude arsenic containing 96.12% arsenic and 1.81% antimony to a small block with a diameter of less than 1 cm, put it into a charging crucible 8, and put the charging crucible 8 into a vacuum tank 7 with a heating device 5 In the process, a condensing tower 4 is placed on the top of the charging crucible 8, and a condensing sheet is set and fixed every 4.7cm in the condensing tower to form 5 equidistant condensing intervals, which correspond to the temperature measuring points. After the condensing tower 4 is installed, install the reaction Cover 1, connected with vacuum device 9, pass CO gas, control pressure at 10000Pa, distillation temperature at 580-620°C, distillation time for 7h, heat up after the pressure is stable, temperature rise rate is 10°C/min, and turn on the cooling water switch at the same time .

During the heating process, the arsenic and antimony in the charging crucible 8 evaporate to form steam, and pass through the condensation tower 4, so that the volatilized antimony vapor and part of the arsenic vapor are condensed on the higher-temperature condensation sheet, and the low-boilers are condensed in the upper part of the furnace. , the arsenic with low antimony content was obtained by collecting arsenic with low antimony content in the middle and low temperature area, and the condensed products were mainly concentrated in the temperature range of 480-310 ° C; after the reaction was completed and the temperature was lowered to below 100 ° C, the cooling water was turned off, the pump was stopped, and the materials were collected; the experiment During the process, the corresponding condensation temperature zones of each condensation plate are 484.8°C in zone I, 436.7°C in zone II, 314.6°C in zone III, 236.1°C in zone IV, and 173.6°C in zone V.

32.8g was collected in zone Ⅰ, 184.8g in zone Ⅱ, 22.5g in zone Ⅲ, 1.2g in zone Ⅳ, 0.9g in zone Ⅴ, 35.4g in the reactor cover, 1.6g in the crucible, and the volatilization rate reached 99.47%. The yield is 70.10%; the obtained arsenic is detected with reference to the non-ferrous metal industry standard TS/T68-2014 of the People's Republic of China by using an inductively coupled plasma mass spectrometer (ICP-MS). %.

Claims (7)

1. A device for vacuum distillation and separation of antimony from crude arsenic, characterized in that it comprises a reactor cover (1), a temperature measuring device (2), a cooling device (3), a condensation tower (4), a heating device (5 ), connecting flange (6), vacuum tank (7), charging crucible (8), vacuuming device (9) and control system (10); The charging crucible (8) and the heating device (5) are placed at the bottom of the vacuum tank (7), and the heating device (5) heats the charging crucible (8) around, and the charging crucible (8) and the heating device ( 5) A multi-stage condensation tower (4) is placed on the top. There are multiple condensation fins and a central screw in the multi-stage condensation tower (4). The condensation fins are fixed on the central screw by nuts. Airflow holes are opened on the sheet, and the airflow holes on two adjacent condensation sheets are arranged oppositely, and a fixed temperature measuring device (2) is provided on the condensation sheet; Above the condensation tower (4) is the reactor cover (1), the reactor cover (1) is connected to the vacuum device (9), the vacuum device (9) is connected to the vacuum tank through the flange, and the reactor cover ( 1) There is a cooling device (3) on the top, and the low boiling point impurities and tail gas are collected on the reactor cover; the whole device is connected with the control system (10). 2. The device for vacuum distillation and separation of antimony from crude arsenic according to claim 1, characterized in that: the vacuum tank (7) and the heating device (5) on the side of the charging crucible (8) are provided with a seal Door for easy removal and insertion of the charging crucible (8). 3. The device for vacuum distillation and separation of antimony from crude arsenic according to claim 1, characterized in that: the multi-stage condensation tower (4) is cylindrical, the condensation sheet is fixed by a gasket, and by adding the gasket Quantity to increase the distance between the condensation fins. 4. The method for vacuum distillation and separation of antimony from crude arsenic by the device according to claims 1 to 3, characterized in that: the raw material is added to the charging crucible (8) in the vacuum tank (7), and the vacuum pumping device is turned on (9) and cooling device (3), the generated steam is condensed in the condensation tower (4), the condensation temperature zone is fully covered from the set temperature to 80°C, and the condensation level is controlled by changing the number and position of the condensation fins Number, stage spacing and condensation temperature zone, so that the volatilized antimony vapor and part of the arsenic vapor are condensed on the higher temperature condensation sheet, and the low boiling point impurities and tail gas are collected on the reactor cover on the upper part of the furnace body; Arsenic is collected with a lower antimony content. 5. The method according to claim 4, characterized in that: the raw material is crude arsenic containing 0.5%-2% antimony and a purity of 96%-98%. 6. The method according to claim 4, characterized in that: the internal pressure of the vacuum tank (7) is 1-10000Pa, the distillation temperature is 400-650°C, and the distillation time is 1-7h. 7. The method according to claim 4, characterized in that: the temperature of the reactor cover (1) is lower than 80°C.

Images