RU2348713C1 - Method of treatment hard gold-arsenical ores and concentrates and furnace for its implementation - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention concerns treatment of hard gold-arsenic ores. Particularly it concerns antimonous sulphide ores and concentrates. Method includes without oxidising melting in smelting chamber with receiving of matte and slag melts and treatment of melting products by metallic phase. At that without oxidising melting is implemented continuously in circulating melted slag with out of melting products into settling chamber to interphase boundary slag - matte. Before melting circulating melted slag is separated from operating gases. For circulating it is used maximum separated from matte slag. Treatment of matte by metallic phase is implemented in continuous operation. Furnace for processing of hard gold -arsenic ores and concentrates includes smelting chamber. Furthermore, it is outfitted by recycling contour, containing of gas-lift unit with tuyeres and descending and ascending channels of melted slag, gas separating and settling chambers. Gas separating chamber is communicated with smelting chamber through bleed blowhole by means of channel for separation of working gas of gas-lift unit and gas separating chamber from circulating melted slag. Smelting chamber immersed into settling chamber to interphase boundary slag - matte. Settling chamber contains gas flue for withdrawal of sublimates and low blowing melting products.

EFFECT: increasing of noble metals extraction into matte.

8 cl, 3 dwg

Description

The group of inventions relates to the field of processing refractory gold-arsenic ores, in particular antimony sulfide ores and concentrates.

A known method of processing refractory gold-bearing arsenic and sulfide-arsenic ores and concentrates, including oxidative calcination followed by cyanide cinder (Maslenitsky I.N., Metallurgy of precious metals, M., Metallurgy, 1972, p. 256).

The disadvantage of this method is the significant loss of precious metals with cyanide tails and the formation of large volumes of environmentally hazardous exhaust gases during firing.

There is a method of processing refractory gold-arsenic ores and concentrates, including melting to obtain matte and slag melts (Mashuryan V.N., Borisova A.G., Strukova N.A. Distribution of gold and arsenic by products of smelting refractory gold-arsenic concentrates, Non-ferrous metals, 1986, No. 3, p. 36-37).

The disadvantage of this method is the low extraction of precious metals in the matte phase and the formation of environmentally hazardous exhaust gases (sulfur and arsenic oxides).

A known method of processing refractory gold-arsenic ores and concentrates, including non-oxidizing smelting with the production of matte and slag melts and washing them with lead (RF Patent No. 2110593, IPC6 С22В 11/02. Publish. 05/10/1998) (prototype).

Non-oxidizing smelting, carried out by a known method, significantly reduces the amount of flue gases and the content of environmentally hazardous products, but does not provide dump slag for the content of noble metals due to incomplete separation of the matte phase from the slag, which dictates its processing by the metal phase (for example, lead) together with matte. At the same time, the technological process is complicated and carried out in periodic mode, which significantly reduces the productivity of the process.

The objective of the invention is to increase the extraction of precious metals in matte, reducing the content of precious metals in the slag to dump values and washing the metal phase only matte in a continuous mode.

The problem is solved in that in a method for the processing of refractory gold-arsenic ores and concentrates, including non-oxidizing melting in a melting chamber to produce matte and slag melts and processing of melting products by metal phase, according to the invention, non-oxidizing melting is carried out continuously in a circulating slag melt with the output of melting products into settling chamber at the phase boundary slag matte;

- before melting, the circulating slag melt is separated from the working gases;

- for circulation use the slag maximally separated from matte;

- processing matte metal phase is carried out in a continuous mode.

The technical result achieved in this case is to increase the extraction of precious metals in matte and reduce the content of precious metals in the slag. This is achieved due to a more complete separation of slag and matte during continuous non-oxidative melting of refractory gold-arsenic ores and concentrates in a circulating slag melt carried out in a melting chamber with the release of melting products into a settling chamber at the slag-matte phase boundary.

The technical result also consists in the fact that only matte is washed with a metal phase in a well while stirring in a continuous phase.

The technical result also consists in increasing productivity in a continuous process.

A known method of melting materials by circulating slag melt. The method is carried out in a furnace containing a loading, gas lift and gas separation chamber (RF Patent No. 2152436, IPC С21В 13/00. Publish. July 10, 2000)

The disadvantage of the furnace is the absence of a settling chamber, which leads to a partial capture of both the feed material itself and the heavy component of the smelting by the circulating flow of slag melt. Materials are melted in a gas separation chamber, which leads to a mixing of the gas transport stream with sublimates.

A known method of processing refractory gold-arsenic ores and concentrates, including non-oxidizing smelting with the production of matte and slag melts and washing them with lead (RF Patent No. 2110593, IPC6 С22В 11/02. Publish. 05/10/1998) (prototype). Smelting in this method was carried out in an induction furnace including a melting chamber.

The disadvantage is that the melting chamber of the furnace operates in a batch mode, which complicates the process and significantly reduces the productivity of the process.

The objective of the invention is to eliminate the mixing of working gases from the gas lift and gas separation chambers and sublimates during melting, to increase the efficiency of phase separation during the treatment of the matte phase with metal melts.

The problem is solved in that in the furnace for processing refractory gold-arsenic ores and concentrates, including a melting chamber, according to the invention, the furnace is equipped with a recirculation circuit consisting of a gas lift with tuyeres and descending and ascending channels of the slag melt, gas separation and settling chambers, while gas separation the chamber is in communication with the melting chamber through an overflow siphon using a channel for separating the working gases of the gas lift and the gas separation chamber from the circulating slag melt, melt Ordering chamber is immersed in the settling chamber at the phase boundary slag-matte, and settling chamber comprises a flue for removing low boilers and sublimates fusion products,

- gas separation chamber contains a channel for a blowing lance or a burner device;

- the settling chamber contains in the lower part of the well with a blowing lance;

- the settling chamber contains a siphon for outputting the metal phase.

In the inventive furnace, slag circulation is carried out sequentially through a recirculation circuit in the composition of the loading-descending and gas-lift chambers, melting and gas separation chambers, a device for removing liquid melting products and a settling chamber. The furnace has two feed channels. Solid fuel (coal) is introduced into one of the loading channels connected to the downward slag melt of the gas lift, and a charge (sulphide concentrate with fluxing additives) is loaded into the other channel connected to the flow of slag melt from the gas separation chamber into the melting chamber. The gas separation chamber is additionally equipped with a channel for installing a blowing tuyere for burning carbon monoxide and entrained carbon or an additional burner for heating circulating slag. The settling chamber in the lower part has a matte collecting well connected to a siphon for its delivery. The well is filled with a molten metal phase to organize the processing of matte. For a more efficient treatment using a blowing lance, a weighted layer of the metal phase in the matte is created. Blow gases from the well are sent to the flue with a built-in reflux condenser

The technical result consists in the fact that in the furnace there is no mixture of the working gas leaving the gas lift and the sublimates from the smelting. Oxidative melting in the furnace is achieved by treating the charge with superheated slag melt in the melting chamber in the absence of gas flows. This allows you to burn solid fuel with an excess of oxygen in both the gas lift and the gas separation chamber, as well as use additional burner devices in the gas separation chamber to heat the circulating slag. The output of the melting products from the melting chamber to the phase boundary of the slag matte of the settling chamber contributes to a more complete phase separation. This leads to a decrease in the mutual entrainment of phases, which contributes to an increase in the extraction of gold in matte. The furnace operates continuously, which increases the productivity of the process.

The inventive design of the furnace is illustrated by drawings, where

figure 1 shows a plan of the furnace,

figure 2 shows a section of a furnace through a gas separation chamber,

figure 3 shows a section of the furnace melting and settling chambers.

The inventive design contains:

- gas lift 1 with tuyeres 2, descending 3 and ascending 4 channels of the slag melt, a gas separation chamber 5, which in the upper part is connected by channel 6 to the ascending channel 4 of the slag melt in the gas lift and has a gas duct 7, overflow siphon 8, channel for the delivery of excess slag 9 and a channel 10 for inputting a blowing lance or a burner device (a blowing lance or a burner device is not shown in the drawings);

- settling chamber 11, which is connected to the downward channel 3 of the slag melt of the gas lift 1 siphon 12 and has a gas duct 13;

- a melting chamber 14, immersed in the bottom of the settling chamber 11 at the interface of the slag and matte, connected by a siphon 8 to the gas separation chamber 5 using the channel 15 and having a loading channel 16 in the upper part.

The descending slag channel 3 has a feed channel 17 in the upper part. The matte phase is discharged from the settling chamber 11 to the well 18 with a suspended metal phase melt layer created by the blowing lance 19, equipped in the upper part with a flue 20 with a reflux condenser 21 for venting the blown gases and returning the sublimated metallophases in the process. The metal phase is removed through a siphon 22. The matte from the well 18 enters the separation chamber 23, which has a feed channel 24 for supplying the metal phase, and the matte delivery channel from the furnace 25. In the lower part, the separation chamber 23 has a channel 26 for transferring the metal phase from the separation chamber 23 into well 18.

The method is carried out in a furnace as follows.

After heating the furnace into the melting chamber 14 through the feed channel 16, pour the necessary amount of metal phase, then matte and then slag. The volume of the metal phase, matte and slag is calculated from the design decisions. During the period of filling the slag melt of the furnace through the tuyeres 2, blast air is supplied to the ascending channel 4 of the gas lift. This starts the controlled recirculation of slag melt between the gas lift chamber 1, channel 6 and sequentially gas separation chamber 5, overflow siphon 8, melting chamber 14, settling chamber 11, through the siphon 12 downward channel 3 of gas lift 1. The furnace is finally heated to operating parameters without loading charge by feeding through the lance 2 a preheated air blast and solid fuel loaded through the feed channel 17 into the downward channel 3 of the downward flow of slag. In the ascending channel 4 of the gas lift 1, solid fuel, for example coal, is burned, followed by its burning and afterburning of carbon monoxide in the gas separation chamber 5 due to air blast supplied through a blow lance installed in channel 10 (the blow lance is not shown in the explanatory drawings). After warming the entire masonry of the furnace and slag to the required temperature, they begin to load the bulk of the charge (sulfide concentrate with fluxing additives) through the feed channel 16 into the melting chamber 14. The volume of the dosed charge is determined from the calculation of the excess heat brought by the slag into the melting chamber 14 for melting the charge, decomposition of higher sulfides and distillation of sublimates while maintaining a liquid slag bath. The slag-matte melt obtained as a result of melting the mixture is stratified due to the difference in density and mutual immiscibility of the slag and matte into the slag and matte (sulfide) phases in the settling chamber 11. Moreover, due to the directed flow of the slag-matte melt down in the melting chamber 14 and the melt is removed from the melting chamber 14 into the settling chamber 11 at the phase boundary of the slag-matte provides a more complete separation of the slag from the matte. Excess slag formed from the mineral component of coal, slag-forming components of sulfide concentrate and fluxing additives is removed from the process through the excess slag discharge channel 9. A part of the slag circulates in the furnace, which is determined by the gas lift capacity. The circulating slag is a heat carrier, transferring heat from the combustion of solid fuel to the melting of the charge. Heat accumulation in the slag occurs when solid fuel is burned in the ascending channel 4 of the gas lift 1 and burned out in the gas separation chamber 5. The foam-liquid phase from gas lift 1 exfoliates in the gas separation chamber 5 into gaseous and liquid phases. Gases are sent to the flue 7, and the liquid phase through a siphon 8 and channel 15 into the melting chamber 14. During the melting of sulfide concentrates in the melting chamber 14, higher sulfides decompose with the formation of elemental sulfur and arsenic. Sublimates are removed from the settling chamber 11 through the gas duct 13. Separation of gas flows from the combustion of solid fuel in the gas lift and gas separation chamber and process gases from the melting of sulfide materials in the melting chamber eliminates the formation of sulfur oxides in both flue and process gases, which greatly simplifies gas cleaning and makes the process environmentally friendly. The matte from the settling chamber 11 enters the well 18 with the metal phase. When passing matte in the well 18 through a suspended layer of metal phase created by supplying inert gas to the well 18 by the blowing lance 19, the noble metals are effectively transferred to the metal phase. The blast gases are removed from the well 18 through the gas duct 20 through the reflux condenser 21. The matte phase from the well 18 enters the separation chamber 23 and then is discharged through the channel 25. A metal phase is introduced into the separation chamber 23 through the loading channel 24. The metal phase is removed through a siphon 22. The efficient processing of the matte by the metal phase with the transition of noble metals from the matte to the metal phase greatly simplifies the further utilization (or processing) of the matte.

The method and operation of the furnace was tested on a laboratory bench. At a furnace temperature of 1400 ° C, 5 kg of a mixture of refractory sulfide-arsenic concentrates of the composition were melted,%: iron - 19.46; sulfur - 12.5; arsenic - 4.88; lead - 0.13; zinc - 0.33; copper - 0.08; aluminum oxide - 10.6; silicon oxide - 33.13; calcium oxide - 2.37; potassium and sodium oxides - 0.89; others - 12.55; gold - 67.33 g / t with the addition of 20% limestone to the concentrate. The matte was washed with an antimony melt. The slag yield from the charge amounted to 60.87%. Slag composition,%: silicon oxide - 48.8; calcium oxide - 28.4%; magnesium oxide - 2.6; aluminum oxide - 14.2%; sodium and potassium oxides - 4.0%; arsenic - 0.2%; sulfur - <0.1; gold - 0.1 g / t. The yield of matte from the charge was 21.9%. The composition of the matte,%; iron - 57.7; arsenic - 0.2%; copper - 0.36; zinc - 0.15; lead - 0.6; sulfur 22.3; other 17.4; gold - 0.05 g / t. The antimony yield, kg, is 0.3 with a gold content of 1.1 kg / t. From the results of the experiments it follows that in the smelting process according to the proposed method in the proposed furnace receive waste slag and matte with a low gold content.

The furnace can be used for processing sulfide concentrates of various compositions, including the processing of antimony-arsenic gold-bearing sulfide concentrates. In addition, the furnace can be used for matte processing of oxidized concentrates and ores, for example, in the processing of pyrite and a number of other technological processes for which it is undesirable to carry out the melting of the charge in the presence of oxidizing gases.

Claims (8)

1. A method of processing refractory gold-arsenic ores and concentrates, including non-oxidizing melting in a melting chamber to produce matte and slag melts and processing of melting products by metal phase, characterized in that the non-oxidizing melting is carried out continuously in a circulating slag melt with the delivery of melting products to the settling chamber at the interface phases slag - matte. 2. The method according to claim 1, characterized in that before melting, the circulating slag melt is separated from the working gases. 3. Method no. 1, characterized in that for circulation use the slag maximally separated from matte. 4. The method according to claim 1, characterized in that the processing of the matte by the metal phase is carried out in a continuous mode. 5. Furnace for the processing of refractory gold-arsenic ores and concentrates, including a melting chamber, characterized in that it is equipped with a recirculation circuit, consisting of a gas lift with tuyeres and descending and ascending channels of the slag melt, gas separation and settling chambers, while the gas separation chamber is in communication with the melting chamber through an overflow siphon using a channel for separating the working gases of a gas lift and a gas separation chamber from the circulating slag melt, the melting chamber is immersed in a settling chamber ru on border slag interface - Matte and drip chamber comprises a gas duct for discharging fumes and low-boiling melting products. 6. The furnace according to claim 5, characterized in that the gas separation chamber contains a channel for a blowing lance or a burner device. 7. The furnace according to claim 5, characterized in that the settling chamber comprises a well with a blowing lance in the lower part. 8. The furnace according to claim 5, characterized in that the settling chamber contains a siphon for outputting the metal phase.

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