RU2385355C1 - Method of germanium extraction - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: method consists in mixing initial charge with germanium containing material, sulphidiser and reducer, in agglomerating and moistening and in a successive electro-melting with periodic charge loading over preliminary induced melt. Melt products are withdrawn from the furnace upon conditioning of melt and producing germanium containing sublimates, sulphide-metal alloy and slag. Upon melting initial charge on surface of melt slag and before its tapping initial charge is loaded into the furnace; also this charge additionally contains sulphide-metal alloy crushed and crumbled to dimension 1.0-0.4 mm before being introduced into charge and conditioned to complete melting. Notably, ashes and carry-over of germanium containing coal burning are used as germanium containing material and reducer; while flux of electric melting of these materials is introduced into charge.

EFFECT: increased extraction of germanium into sublimates and increased ratio of sublimates concentration.

2 cl, 3 tbl, 2 ex

Description

The invention relates to the field of metallurgy of dispersed metals, mainly to the field of processing of germanium-containing raw materials, in particular sulfide-metal alloy - a by-product of electric melting of fly ash and dust from the combustion of germanium-containing coals.

In the process of electric melting of germanium-containing raw materials are formed:

- a melt of slag accumulating the main macrocomponents of raw materials and additives, into which 2-4% of Germany passes;

- iron-based sulfide-metal melt (“korolek”), formed as a result of sulfidation and partial reduction of iron oxides by carbon of the charge and graphite electrodes, into which 5-6% of germanium passes;

- sublimates resulting from the oxidation of germanium monosulfide and the deposition of dioxide on the surface of particles of mechanical entrainment of the charge, into which up to 90% of germanium passes; the rest of Germany represents mechanical losses in the preparation and transportation of raw materials, charge and loss of sublimates through the fabric of bag filters during gas purification. Sublimates are sent to oxidative calcination to obtain a germanium concentrate.

Sulfide-metal alloy ("korolek") on average contains from 0.5 to 2% germanium, 0.2-10% sulfur, 5-20% silicon, 50-70% iron, the rest is impurities. This product is essentially biphasic and consists of a sulfide phase based on a Fe-S melt and a metal phase, which is a melt of the Fe- (Si, P, C) -S system. The ratio of sulfide and metal components of the “king” depends on the composition of the raw material and the mixture, the basicity of the slag, the temperature and can vary over a wide range (from 1:10 to 10: 1). The sulfide part of the "king", as a rule, contains 10-50 times less germanium than the metal.

In industrial practice, a separate (in mold) or joint with slag release of a sulfide-metal alloy from an electric furnace is used, followed by water granulation of the melts. There is currently no technology for processing a sulfide-metal alloy.

The present invention relates to the processing of a solid sulfide-metal alloy after separate production of a sulfide-metal alloy. If the enterprise does not have an aggregate for processing primary germanium-containing carbon raw materials (coal, mudstone and siltstone) by combustion methods, for example, a layered or cyclone combustion chamber, the sulfide-metal alloy is not processed and goes to the dump for storage, which reduces through extraction of germanium. An increase in the total extraction of germanium can be achieved by the development of a technology for additional extraction of germanium from this waste in an electric furnace, which is used for the main process - smelting of products of combustion of primary raw materials.

A known method of extracting germanium from an iron-based alloy by chlorination in a solution of iron chloride (ARPowell, FVLever, REWalpole. The Extraction and Refining of Germanium and Gallium. Journal of Applied Chemistry, VI, No.12, 1951, pp.541- 555).

The disadvantages of the method are:

- the use of toxic reagents;

- low productivity due to the low dissolution rate of the alloy containing silicon and phosphorus;

- the formation of gaseous sulfur compounds, which complicates the purification of germanium tetrachloride;

- the need to neutralize chloride solutions;

- the mandatory presence in the technological scheme of processing of germanium-containing raw materials redistribution of cyclone smelting;

- limited 3-15% content of the additive in the mixture.

The listed disadvantages of analogues do not allow their effective use for the extraction of germanium from a sulfide-metal alloy.

The closest analogue is a method for the extraction of germanium (RF patent No. 2058409), comprising mixing the initial charge containing a germanium-containing material, a sulfidizing agent and a reducing agent, agglomeration with humidification, subsequent electric melting with periodic loading of the charge into the furnace to produce sublimates, a sulfide-metal alloy and slag, output of smelting products from the furnace Before melting, the initial charge in the process of agglomeration is moistened to a moisture content of 25-30%. Melting is carried out while maintaining on the melt surface a charge layer with a thickness of 0.1-0.3 m when it is heated at a speed of 5-20 ° C / min. The amount of sulfur in the initial charge is supported by 3-8%. Carbon reducing agent in the amount necessary for the process (5-8% in the charge), as a rule, is contained in the composition of the raw material. With a lack of reducing agent, it is introduced in the form of coal or coke.

The disadvantages of the closest analogue in relation to the processing of sulfide-metal alloy from separate production are:

- obtaining slag with a high content of iron oxide, which leads to an increase in the germanium content in the slag;

- increase the yield of the secondary sulfide-metal alloy and the germanium content in it;

- insufficient multiplicity of enrichment of sublimates, which does not allow to obtain a material suitable for the production of standard concentrate;

- low germanium recovery (not more than 20-30%), which leads to unacceptable technical and economic indicators.

The objective of the present invention is to provide a method that allows to process a sulfide-metal alloy with obtaining sublimates that meet the requirements for sublimates used for the production of germanium concentrates, the content of germanium, as well as to increase the through extraction of germanium in order to achieve technical and economic indicators that provide an increase profitability of production.

The technical result of the invention is:

- increase the extraction of germanium into sublimates in the processing of alloy and through extraction of germanium from raw materials,

- increase the multiplicity of enrichment of sublimates.

The specified technical result is achieved by the fact that in the method of extracting germanium, comprising mixing the initial charge containing germanium-containing material, a sulfidizing agent and a reducing agent, agglomeration with moistening, subsequent electric melting with periodic loading of the charge into the furnace to produce sublimates, a sulfide-metal alloy and slag, output products melting from the furnace, according to the invention, after the initial charge is melted onto the surface of the slag melt, before its release, the initial mixture is loaded into the furnace, additionally rzhaschuyu sulfide-metal alloy, which before the introduction into the batch crushed and milled to a particle size 1,0-0,4 mm, and it is maintained until complete melting.

In addition, as a germanium-containing material and a reducing agent, ash and fly ash from the combustion of germanium-containing coals are used, and a flux is introduced into the charge, which is used as an electric melting slag of these materials.

Grinding the alloy to a particle size of 1 mm or less makes it possible to extract germanium into sublimates from the alloy at a level of about 90% or more, grinding to a particle size of less than 0.4 mm is impractical, since it does not significantly increase the processing rates and requires additional costs.

Downloading the agglomerated charge with the alloy on the surface of the slag melt of the main smelting of germanium-containing ash and fly ash before its release provides secondary slag with a low content of iron oxide. Due to this, the germanium content in the secondary slag is reduced. In addition, the secondary alloy is depleted in Germany. As a result, the extraction of germanium from the sulphide-metal alloy and the overall recovery of germanium are increased.

The use of germanium-containing carbon materials and slag from their processing can reduce the cost of auxiliary materials and increase the total amount of germanium involved in the processing.

The possibility of carrying out the invention is illustrated by the following examples.

Example 1

The sulfide-metal alloy was processed according to the invention and the closest analogue. Previously, the alloy was crushed to a piece size of 20 mm, then part of the alloy for processing according to the invention was crushed to a particle size of 0.7 mm. Comparative testing was carried out on laboratory models of a vibrating grinder, drum pelletizer, briquette press and electric furnace equipped with a gas exhaust system with air supply for oxidizing sublimates and filtering gas in a bag filter with Polin 7 filter cloth. Testing of the heat was carried out in periodic mode.

The composition of the charge was taken from the calculation of the sulfur content in the charge equal to 5%. Calcium sulfate hemihydrate (alabaster) was used as a sulfidizing agent, and coarse dust of layer burning (battery entrainment) as a carbon reducing agent and a slag-forming component. Calcium oxide from alabaster, as well as electric smelting slag of germanium-containing fly ash of layered brown coal burning, served as fluxes to obtain the slag necessary for melting the composition. These two materials were also components of a binder for sintering the mixture. The compositions of the materials used are shown in table 1.

Table 1 Material Composition Material Content, dry weight,% Ge, g / t Si (SiO ₂ ) Cao MgO Al ₂ O ₃ Fe S FROM Sulfide metal alloy 12300 11.7 2.6 1,1 0.5 52,2 1,5 1,0 Layered Ash (Reducer) 18053 47.2 2,8 1,0 16.6 3.6 1,1 9.7 Battery entrainment (reducing agent) 989 (51.1) 1.9 0.8 13.0 4.1 0.3 15.6 Electric smelting slag (flux) 52 (41.7) 26.7 1,0 10.0 3.3 1.3 1,2 Alabaster (sulfidization) 0 (3,5) 37,2 0,0 1,2 1.9 17.4 0,0

The components of the mixture in accordance with the closest analogue were subjected to mixing, moistening and agglomeration by pelletizing or briquetting at a pressing pressure of 500 kg / cm ² . When processing the alloy in accordance with the invention, the mixture was subjected to mixing and grinding, moistening and sintering in the same ways. The finished mixture was sent for melting.

The heating rate of the agglomerated charge in an electric furnace in accordance with the closest analogue was maintained at 20 deg / min to a temperature of 1550 ° C, followed by exposure of the melts at this temperature for 30 minutes. Next, an agglomerated charge containing a sulfide-metal alloy was loaded onto the surface of the molten slag of the electric melting at a temperature of 1550 ° C and kept until completely melted. The processing results according to the invention and the closest analogue are shown in table 2.

From a comparison of the data of table 2 shows that the use of the invention allows:

- reduce the germanium content in the processing waste: secondary alloy by 5-6 times, slag 50-60 times due to the reduction of FeO content by 1.3 times;

- increase the extraction of germanium in sublimates from the alloy from 4.7 to 90% and the total extraction of germanium from the components of the charge from 7.4 to 88.6%;

- increase the multiplicity of enrichment of sublimates with Germany by 7.7 times.

table 2 Comparison of Sulfide-Metal Alloy Processing №№ pp The name of indicators Units rev. Indicator values proposed invention nearest analogue one Alloy grinding time min twenty 0 2 Particle size of alloy before blending mm 0.7 20,0 3 The composition of the charge: % alloy - "- 32.9 45,2 alabaster - "- 36.5 35.3 battery ablation - "- 14.1 19.5 electric smelting slag - "- 16.5 - four The mass of the molten slag from the mass of the alloy in the mixture % 300 - 5 The humidity of the pellets (briquettes) according to the invention, the mixture according to the closest analogue % 25 (16) 27 (16) 6 The strength of the pellets (briquettes) after agglomeration on compression N / pellet (N / cm ² ) 50 (150) 10 (25) percussion by dumping from 2 m onto a cast-iron plate to failure time 3 (3) 1 (1) 7 The yield of processed products (from the mass of the alloy) % 8 slag - "- 523.8 130.1 9 secondary alloy - "- 53.6 72.7 10 sublimates - "- 7.43 4.65 eleven FeO content in slag - "- 6.2 8.1 12 Germany content 13 slag g / t twenty 1139 fourteen secondary alloy - "- 2550 14186 fifteen sublimates % 15.40 2.01 16 Germany extraction into sublimates % 17 alloy - "- 90.0 4.7 eighteen common of charge components - "- 88.6 7.4

Example 2

The sulfide metal alloy was processed according to the invention. Preliminarily, the alloy was crushed to a piece size of 20 mm, then it was crushed to a particle size of 1.5 to 0.2 mm. A comparative test was carried out as in example 1. The processing results (table 3) showed that:

- grinding the alloy to a particle size of 1 mm or less makes it possible to achieve germanium recovery into sublimates from the alloy at a level of about 90% or more;

- reduce the loss of germanium with secondary slag (1.8 times) and the alloy (1.2 times), increase the total germanium extraction into sublimates from the charge components from 75% (when grinding the alloy to 1.5 mm) to more than 90% (when grinding to 0.4 mm or less);

- grinding the alloy to a particle size of less than 0.4 mm is impractical, since it does not significantly increase the processing rates and requires additional time, material and energy costs.

Table 3 Dependence of yields and compositions of products of processing a sulfide-metal alloy on the size of its particles after grinding The particle size of the alloy, mm The yield of smelting products,% by weight of the alloy Ge content, g / t Ge recovery in sublimates,% slag secondary alloy sublimates alloy from slag common of charge components 1,5 505.6 79.0 7.4 32 3850 130300 75.6 11.1 75.0 1,2 514.5 66.3 7.4 26 3210 142003 85.3 26.1 81.7 1,0 519.0 60.0 7.4 23 2885 147929 89.9 33.9 85.1 0.7 523.8 53.6 7.4 twenty 2550 154003 90.0 42,4 88.6 0.4 526.1 50.8 7.4 eighteen 2399 156701 90.1 47.0 90.1 0.2 526.3 51.1 7.4 eighteen 2400 156623 90.3 47.9 90.1

Claims (2)

1. A method of extracting germanium, comprising mixing the initial mixture containing germanium-containing material, a sulfidizing agent and a reducing agent, agglomeration with moistening, subsequent electric melting with periodic loading of the mixture into a furnace to obtain germanium-containing sublimates, a sulfide-metal alloy and slag, output of melting products from the furnace, different the fact that after the initial charge is melted, the initial charge, additionally containing a sulfide-metal alloy, is loaded onto the surface of the slag melt before being released into the furnace lava, which is crushed and ground to a particle size of 1.0-0.4 mm before being introduced into the charge, and maintained until it is completely melted. 2. The method according to claim 1, characterized in that as a germanium-containing material and a reducing agent, ash and fly ash from the combustion of germanium-containing coals are used, and a flux is introduced into the charge, which is used as an electric melting slag of these materials.