CN101876005B - Method for extracting gold from refractory sulfide ore gold concentrate by two-stage pressurized oxygen leaching - Google Patents

Abstract

The invention relates to a method for extracting aurum from difficult-to-handle sulphide ore aurum concentrate by two-segment pressurization leaching method comprising two segments of pressurization oxidation preprocessing and pressurization oxidation aurum leaching. The method comprises the steps of: firstly, pressurizing and oxidizing base metal sulfide such as iron sulfide with sulfuric acid-iron sulfate, wherein most S2- and S22- are oxidized into elemental sulfur; and secondly, pressurizing and leaching the preprocessed slag with thiocyanate so that aurum is selectively dissolved in the solution in the form of aurum-thiocyanic acid compound. Therefore, the pre-oxidation slag can be directly leached without neutralization, the technical process is short, the aurum recovery rate is high, the cost is low and pollution of low-concentration SO2 smoke gas, As2O3 smoke dust, and the like is avoided.

Description

Method for extracting gold from refractory sulfide ore gold concentrate by two-stage pressurized oxygen leaching

technical field

The invention belongs to non-ferrous metal wet extraction metallurgy and is suitable for extracting gold from refractory sulfide ore gold concentrate. the

technical background

Refractory gold ore reserves account for 30% of the world's total gold ore reserves, and my country accounts for more than 20%, of which arsenic-containing refractory gold ore accounts for the vast majority. There is no successful precedent for direct cyanidation selective leaching of gold. At present, the treatment plan for arsenic-containing refractory gold concentrate is basically oxidation pretreatment first, and then cyanide leaching of gold. There are four oxidation pretreatment schemes: chemical oxidation, roasting, pressurized oxidation and bacterial oxidation. Biological pretreatment-cyanide method (Yang Hongying, et al. Oxidative pretreatment of high-arsenic complex and refractory gold ore by arsenic-resistant bacteria-cyanide gold extraction method, CN 200810011233.6; Gao Jinchang, et al. Biopile of low-grade refractory gold ore Gold leaching process, CN 200810050452.5) Firstly, the ore of gold-containing minerals is crushed, granulated, and piled, and then the ore is treated with acid, and then the ore is used to carry out biological pre-oxidation with microorganisms. Chemical leaching, and finally gold recovery. The advantage lies in low cost and low energy consumption, but the biological treatment speed is slow, and the mineral needs to be converted from acidic to alkaline after treatment. Oxidative roasting-cyanidation method (Chen Liangzhong, Yang Zhengkun. Kiln-style oxidative roasting and gold extraction integrated process for refractory gold ores, ZL 200610048718.3) The roasting treatment of refractory gold ores and the atmospheric pressure cyanidation gold extraction treatment are all in the same tunnel kiln In the production process, it is inevitable to produce low-concentration SO ₂ flue gas and smoke dust containing highly toxic As ₂ O ₃ , and there are also disadvantages such as low gold recovery rate. Du Qinye and others proposed to use oxygen pressure pretreatment-cyanidation method (a method for extracting gold and silver from refractory gold and silver concentrates, ZL 03112127.6) to extract gold and silver from refractory gold and silver concentrates, In this method, first add 69-253g of sulfuric acid and NaCl 0.01-0.08g/L solution, leaching in the tank for 3 hours to remove CO ₂ ; catalytic oxidation acid leaching at a temperature of 96-106°C and an oxygen pressure of 0.16-0.6MPa, After adding sulfuric acid, nitric acid and sodium lignosulfonate, pickle in an autoclave for 1-4 hours; add water, lime and sodium lignosulfonate to the remaining elemental sulfur in the oxidized residue, at 80-100℃, oxygen pressure 0.1-0.4 Under MPa, desulfurize by leaching for 0.5-3 hours; add NaCN, lime and oxygen to the pulp after pressure filtration for 24-48 hours. The main problems of this process are that in order to extract gold by cyanidation, it is necessary to completely oxidize S ^2- to SO ₄ ^2- to convert S _x ^2- (x≥2) into the solution, so the process is long and the equipment is severely corroded. Their further literature reports (Li Xueqiang, et al. Research and application of catalytic oxidation acid leaching method for arsenic-containing refractory gold and silver concentrates. Modern Mining Industry, 2009, (1): 37-40) showed that catalytic oxidation acid leaching During the process, more than 5.5g/L of HNO ₃ needs to be added. When nitric acid is used as a catalyst, it will be reduced to NO after participating in the reaction. NO in the gas phase reacts with O ₂ to quickly generate NO ₂ and return to the liquid phase to become HNO ₃ . The main reaction simplifies to:

4FeS ₂ +15O ₂ +2H ₂ O＝2Fe ₂ (SO ₄ ) ₃ +2H ₂ SO ₄ (1)

2FeAsS+H ₂ SO ₄ +7O ₂ +2H ₂ O=Fe ₂ (SO ₄ ) ₃ +2H ₃ AsO ₄ (2)

Although the amount of NO ₃ ^- added by this process is less than the NO ₃ ^- 250g/L of the Arseno method, the NO ₃ ^- 250g/L of the Nitrox method and the 70-110g/L of the Redox method, there are also serious equipment corrosion and toxic of nitrogen oxide gas. The above leaching of gold by cyanide method requires the use of highly toxic sodium cyanide, which has serious environmental protection problems; in addition, in the process of processing sulfide ore pretreatment slag, if the sulfur removal in the pretreatment process is not complete, the remaining in alkaline conditions Sulfur will be oxidized to S ₂ O ₃ ^2- or react with CN ^- to generate SCN ^- , increasing the consumption of cyanide. Ouhuabei (Wet pretreatment of refractory gold ores containing arsenic and antimony and cyanide-free gold extraction method, ZL 200610008781.4) proposed chlorination pretreatment-thiosulfate method to treat refractory gold ores containing arsenic and antimony, using bleaching powder , sulfuric acid, hydrochloric acid or chlorine gas hydrochloric acid, hydrogen peroxide or perchloric acid, hydrochloric acid, hydrogen peroxide or hydrochloric acid, hydrogen peroxide mixed solution containing 1.5-10% of active chlorine is aged at 40-80 ° C and pH < 1 condition 3 For more than one day, the ammoniacal thiosulfate solution made of 0.2-1.0mol of thiosulfate, 0.4-1mol of ammonia, 0.04-0.1mol of sulfite and 0.4-1g of copper ions in the pretreatment slag is at pH 9-11. At a temperature of 40-50°C, leaching for 8-20 hours, the leaching solution uses activated carbon to adsorb gold. This process has the disadvantages of large consumption of reagents and serious corrosion of equipment by chlorides.

For thiocyanate leaching gold at normal temperature and pressure, AGKholmogorov et al. (Thiocyanate solutions in gold technology. Hydrometallurgy, 2002, 64: 43-48) used 0.4mol/L KSCN solution to leach gold-containing arsenopyrite concentrate prepared by chemical method , leaching for 3-4 hours under the condition of pH value 2-5, the leaching rate of gold is greater than 95%. AJMonhemius et al. (Leaching of gold in thiocyanate solutions, Part 2: redox processes in iron(III)-thiocyanate solutions. Transactions of the Institution of Mining & Metallurgy, Section C, 1994, 103, pp.C111-C116) proposed the use of thiocyanate Solution leaching gold, using Fe ³⁺ as oxidant, has a higher leaching speed and leaching rate in the pH range of 2-3, but SCN ^- is oxidized and Fe ³⁺ is reduced to Fe ²⁺ . AJMonhemius et al. (Leaching of Dominican gold ores in iodide-catalysed thiocyanate solution. Transactions of the Institution of Mining and Metallurgy, Section C, 1995, 104, C117-C124) also proposed to use iodine as an oxidizing agent to leach gold. A series of patents such as Rong Yu Wan (Precious metal recovery using thiocyanate lixiviant.US20080066577, 2007-10-3; US 20080066578, 2007-10-5; US 20040197249, 2003-8-28) proposed the use of biological pretreatment, thiocyanate Treatment of gold-bearing sulfide ores by heap leaching in salt solution. The use of thiocyanate oxygen pressure leaching of gold has not been reported in the literature.

Contents of the invention

At present, the technologies reported in the literature for processing refractory gold sulfide concentrates mainly have the following disadvantages, such as long flow process, low recovery rate, highly toxic reagents, and serious equipment corrosion. The two-stage pressurized oxygen leaching method for metal and thiocyanate system pressurized oxygen leaching to extract gold from refractory gold sulfide concentrate has the advantages of short process, environmental friendliness and high recovery rate. the

The purpose of the present invention is achieved in the following manner:

The two-stage pressurized oxygen leaching method is a method for extracting gold from refractory gold sulfide concentrates, using a two-stage pressurized oxygen leaching method, which is divided into pressurized oxygen leaching pretreatment and pressurized oxygen leaching gold from refractory sulfide gold concentrate. Extraction of gold from gold concentrate; the first stage of pressurized oxygen leaching pretreatment, using the sulfuric acid-ferric sulfate solution mixed with the first stage filtrate of the previous pressurized oxygen leaching pretreatment after adding industrial sulfuric acid as the leaching agent, and pressurized Oxidation leaching to obtain the first stage filtrate containing iron and other impurity metals and pretreatment slag containing elemental sulfur and Au; the second stage pressurized oxygen leaching gold leaching is to use the pretreatment slag and then use thiocyanate containing iron ions The acid salt solution is used as the leaching agent for pressurized oxygen leaching, so that the gold is selectively dissolved in the form of gold-thiocyanate complex and enters the second stage of filtrate. the

In the first stage of pressurized oxidation leaching process: the composition of the leaching agent is iron 1-30g/L, SO ₄ ^2-0.5-3mol /L; the amount of gold concentrate is 80-350g/L, and Zhan gold concentrate is added 0.05-0.5% sodium lignosulfonate by weight, controlled oxygen pressure 0.4-1.8Mpa, temperature 100-180°C, reacted for 0.5-4.0 hours, and then separated the solid and liquid after cooling down.

In the second stage of the pressurized oxidation leaching process: the leaching agent is 0.05-5.0mol/L containing thiocyanate, 0-10g/L iron ion; the amount of gold concentrate pretreatment slag added is 80-300g/L, Add it into the reaction kettle and adjust the pH value to 1.0-5.0 with industrial sulfuric acid or lime after mixing; control the temperature of the reaction kettle at 100°C-180°C, feed oxygen to maintain the pressure in the reaction kettle at 0.4-2.0MPa, and react for 1.0-6.0 hours; cool down After solid-liquid separation and washing, gold is recovered from the leaching solution, and the recovered gold solution is returned to pressurized oxygen leaching. the

The present invention proposes a two-stage pressurized oxygen leaching method for pressurized oxidation of iron and other base metal sulfides and thiocyanate solution in a sulfuric acid system to leaching gold from refractory sulfide gold concentrates. Extract gold from the mine. the

Basic principle of the present invention is:

①Pretreatment of refractory gold sulfide concentrate by pressurized oxygen leaching in sulfuric acid system, using the iron-containing solution obtained from the previous pressurized oxidation of refractory gold concentrate in the return part, and then adding water, industrial sulfuric acid, and an appropriate amount of sodium lignosulfonate, adding Most of S ^2- , S ₂ ^2- are oxidized to elemental sulfur when oxidizing iron and other base metal sulfides. Major reactions include:

4Fe ²⁺ +O ₂ +4H ⁺ ＝4Fe ³⁺ +2H ₂ O (3)

FeS ₂ +2Fe ³⁺ ＝3Fe ²⁺ +2S ⁰ (4)

FeAsS+5Fe ³⁺ +6H ₂ O＝6Fe ²⁺ +2H ₃ AsO ₃ +2S ⁰ +6H ⁺ (5)

MeS+2Fe ³⁺ =Me ²⁺ +2Fe ²⁺ +S ⁰ (6) Me represents zinc, copper, lead, and the like. By returning part of the previous pretreatment of the iron-containing solution, the reaction rate can be significantly increased, and the product obtained by S2 ^- oxidation is elemental sulfur, while avoiding the strong corrosiveness of the catalyst nitric acid. If the refractory minerals contain carbonates of Ca and Mg, they should be stirred and decomposed under normal pressure in the reactor first, and then oxygenated.

②The thiocyanate system selectively leaches gold from the pretreatment slag of refractory sulfide ore gold concentrate by pressurized oxidation, using Au ⁺ , Au ³⁺ and SCN ^- to form very stable complexes Au(SCN) ₂ ^- , Au(SCN) ₂ ⁺ , Au(SCN) ₄ ^- , oxygen, Fe ³⁺ and other oxidizing agents oxidize gold and then form stable complexes with SCN ^- to enter the solution.

4Au+8SCN ^- +O ₂ +2H ₂ O＝4Au(SCN) ₂ ^- +4OH ^- (7)

4Au+8SCN ^- +3O ₂ +6H ₂ O＝4Au(SCN) ₂ ^- +12OH ^- (8)

2Au ₂ S+8SCN ^- +O ₂ +2H ₂ O＝4Au(SCN) ₂ ^- +4OH ^- +S ⁰ (9)

Au+2SCN ^- +Fe ³⁺ ＝Au(SCN) ₂ ^- +Fe ²⁺ (10)

The elemental sulfur oxidized in the pretreatment process not only does not affect the leaching rate of gold in the oxygen pressure leaching gold process, but also plays a role in stabilizing the leaching agent ^SCN- , because if there is no elemental sulfur, the oxygen pressure leaching gold process will occur The following response:

(SCN) ₂ +2e ^- ＝2SCN ^- (11)

(SCN) ₃ ^- +2e ^- ＝3SCN ^- (12)

3(SCN) ₂ +4H ₂ O＝5SCN ^- +HCN+7H ⁺ +SO ₄ ^2- (13)

3(SCN) ₃ ^- +4H ₂ O＝8SCN ^- +HCN+7H ⁺ +SO ₄ ^2- (14)

In the presence of elemental sulfur, the following reactions can occur:

CN ^- + S ⁰ = SCN ^- (15)

3(SCN) ₂ +S ⁰ +4H ₂ O＝6SCN ^- +SO ₄ ^2- +8H ⁺ (16)

Inhibit and eliminate the decomposition reaction of thiocyanate. the

Sulfuric acid system pressurized oxygen leaching pretreatment of refractory gold sulfide concentrate, the technical conditions of the first stage of pressurized oxygen leaching are as follows: the iron-containing part obtained from the previous pressurized oxygen leaching pretreatment of refractory gold concentrate in the return part Add industrial sulfuric acid and water to one stage of filtrate to prepare a leaching agent containing iron 1-30g/L, SO ₄ ^2- 0.5-3mol/L, the amount of gold concentrate is 80-350g/L, and the weight of gold concentrate is 0.05- 0.5% sodium lignosulfonate, control oxygen pressure 0.4-1.8Mpa, temperature 100-180°C, react for 0.5-4.0 hours, and then separate solid-liquid after cooling down. Part of the filtrate in the first stage is open-circuited to recover ferrous sulfate, and part of it is returned to the pretreatment process of pressurized oxygen leaching.

The second stage of thiocyanate system pressurized oxygen leaching for gold leaching uses thiocyanate solution containing iron ions as the leaching agent: 0.05-5.0mol/L of cyanate, 0-10g/L of iron ions; The amount of concentrate pretreatment slag added is 80-300g/L, and it is added to the reactor for mixing, and then the pH value is adjusted to 1.0-5.0 with industrial sulfuric acid or lime; the temperature of the reactor is controlled at 100°C-180°C, and oxygen is fed into the reactor to maintain The air pressure is 0.4-2.0MPa, and the reaction is 1.0-6.0 hours; after cooling down, the solid-liquid is separated and washed, and then the gold is recovered from the leaching solution by iron powder replacement, activated carbon adsorption or extraction. The solution after recovery of gold is returned to pressurized oxygen leaching for gold. the

The present invention adopts the two-stage pressurized oxygen leaching method to extract gold from refractory sulfide ore gold concentrate, and the purpose of using thiocyanate system pressurized oxygen leaching to leach gold is that the gold in the sulfide gold concentrate pretreatment slag is replaced by Au The form of (SCN) _n ^(n-1) -complex dissolves into the leaching solution, while other base metal elements remain in the leaching residue. The leaching selectivity of gold is good, and the leaching of impurity elements is less. The pH range of the complex formed between thiocyanate and gold ions is greater than 1.0. However, if the pH is too high, elemental sulfur and metal sulfides are easily oxidized into sulfate and thiosulfate.

The leaching agent used for the first stage pretreatment of the present invention is a sulfuric acid-ferric sulfate solution mixed with a part of the filtrate of the pressurized oxygen leaching pretreatment before the addition of industrial sulfuric acid. If part of the iron-containing filtrate produced by the previous pressurized oxidation pretreatment is returned, the return amount should be determined according to the iron content of the leaching agent. the

The refractory gold sulfide concentrate is a gold concentrate containing refractory sulfides such as high-arsenic pyrite, antimony sulfide or copper sulfide, such as: high-arsenic sulfide gold concentrate, copper-containing sulfide ore gold concentrate, Refractory gold ore containing arsenic and antimony, etc. the

The thiocyanate of the present invention is ammonium thiocyanate, potassium thiocyanate or sodium thiocyanate, and the concentration of thiocyanate is 0.05-5.0mol/L. the

For refractory gold sulfide concentrates containing carbonate minerals such as Ca and Mg, first stir and decompose in the reactor under normal pressure to release CO ₂ , and then pressurize oxygen leaching with oxygen.

The filter residue obtained from the second stage of pressurized oxygen leaching is processed to recover sulfur and other valuable metals. the

Compared with the prior art, the present invention adopts a two-stage pressurized oxygen leaching method. The pre-oxidized slag can be directly leached into gold without neutralization. It has the advantages of short process, less reagent consumption, no three waste pollution, and easy industrialization. advantage. And the present invention also has the following multiple effects by returning the first section to the previous pretreatment part of the iron-containing solution, that is, this treatment method can not only significantly improve the reaction speed, but also make the product obtained by S2-oxidation be elemental sulfur, and at the same time Avoid the strong corrosiveness of the catalyst nitric acid; at the same time, the elemental sulfur generated by oxidation during the pretreatment process not only does not affect the gold leaching rate in the second stage of the pressurized oxygen leaching process, but also plays a role in stabilizing the leaching agent ^SCN- , The effect of inhibiting and eliminating the decomposition reaction of thiocyanate.

Detailed ways

The following examples are intended to illustrate the invention without further limiting the invention. the

Example 1:

The chemical composition (mass fraction, %) of a high-arsenic and low-grade gold sulfide concentrate from a mine in Hunan is as follows: As10.02, S 36.40, Fe 42.43, Zn 1.05, Si 3.69, Al 0.98, Mg 0.85, Ca 1.21, Au 24.62 g/t. the

Pressure oxidation pretreatment conditions: leaching agent containing Fe ³⁺ 20.0g/L, SO ₄ ^2- 1.5mol/L, gold concentrate 150g/L, adding 0.4% gold concentrate sodium lignosulfonate, controlling Oxygen pressure 1.4Mpa, temperature 160°C, reaction for 1.0 hour, liquid-solid separation.

Pretreatment slag ammonium thiocyanate solution leaching conditions: NH ₄ SCN 0.2mol/L solution, Fe ³⁺ 2.0g/L, pretreatment slag addition 150g/L, add to the reactor and mix with industrial sulfuric acid or lime to adjust pH value to 2.5; control the temperature of the reactor to 160°C, feed oxygen to maintain the pressure in the reactor at 1.4MPa, and react for 1.0 hour; after cooling down, separate the solid and liquid, wash, the gold content in the slag is less than 4g/t, and the gold leaching rate is greater than 90 %. Calculating 10 times the amount of gold, add iron powder to replace gold from the leaching solution, stir at room temperature for 1 hour, the replacement rate is greater than 99%, and after replacement, the solution returns to pressurized oxygen leaching for gold.

Example 2:

The chemical composition (mass fraction, %) of gold sulfide concentrate produced by a certain mine is as follows: As 6.2, S 14.48, Fe 13.64, Cu 0.05, Si 34.2, Al 3.2, Mg 1.15, Ca 2.11, Au 65.89g/t. the

Pressure oxidation pretreatment conditions: leaching agent containing Fe ²⁺ 9.0g/L, SO ₄ ^2- 1.0mol/L, gold concentrate amount 300g/L, adding 0.08% gold concentrate amount of sodium lignosulfonate, control Oxygen pressure 1.0Mpa, temperature 130°C, reaction for 4.0 hours, liquid-solid separation.

Pretreatment slag ammonium thiocyanate solution leaching conditions: NH ₄ SCN 0.8mol/L solution, Fe ³⁺ 4.0g/L, pretreatment slag addition 300g/L, add to the reactor and mix with industrial sulfuric acid or lime to adjust pH value to 1.5; control the temperature of the reactor to 120°C, feed oxygen to maintain the pressure in the reactor at 1.0MPa, and react for 6.0 hours; after cooling down, solid-liquid separation and washing, the slag contains 4.1g/t of gold, and the gold leaching rate is 94.4% . According to the extraction V _{organic phase} /V water phase = 2/10, 3-stage extraction, the extraction rate of gold is greater than 98%, and the raffinate is returned to pressurized oxygen for gold leaching.

Example 3:

The chemical composition (mass fraction, %) of a mineral sulfide gold concentrate is as follows: As 0.56, S 8.48, Fe 11.34, Cu 0.04, Al 1.25, Mg 10.02, Ca 4.87, Au 83.78g/t, Ag 1252g/t. the

Pressure oxidation pretreatment conditions: leaching agent containing Fe ³⁺ 3.0g/L, SO ₄ ^2- 3.0mol/L, gold concentrate 200g/L, adding 0.1% gold concentrate sodium lignosulfonate, first At 90°C, react under normal pressure for 1 hour to decompose the carbonate, then control the oxygen pressure to 0.8Mpa and the temperature to 140°C, and react for 2.0 hours to separate the liquid and solid.

Pretreatment slag ammonium thiocyanate solution leaching conditions: NH ₄ SCN 4.0mol/L solution, Fe ³⁺ 8.0g/L, pretreatment slag addition 200g/L, add to the reactor and mix with industrial sulfuric acid or lime to adjust pH value to 1.8; control the temperature of the reactor to 140°C, feed oxygen to maintain the pressure in the reactor at 1.2MPa, and react for 3.0 hours; after cooling down, solid-liquid separation and washing, the gold content in the slag is less than 6g/t, and the gold leaching rate is greater than 95 %. Adding 5g of activated carbon per liter of leachate to absorb gold from the leachate, stirring at room temperature for 2 hours, the adsorption rate of gold is greater than 98.0%, and the solution can be returned to the pressurized oxygen leaching of gold.

Example 4:

The chemical composition (mass fraction, %) of a refractory gold concentrate containing arsenic and antimony in a mine in Guangxi is as follows: As5.77, S 12.78, Fe 11.34, Sb 1.25, C 5.45, Cu 0.05, Al 1.1, Mg 0.04, Si 22.7, Ca 1.38, Au 113g/t, Ag 697g/t. the

Pressurized oxidation pretreatment conditions: the iron-containing (mainly Fe ²⁺ ) 18.01g/L solution obtained from the previous pressurized oxygen leaching pretreatment of refractory gold concentrate, adding industrial sulfuric acid and water to make an iron-containing 5.0g/L , SO ₄ ^2- 0.8mol/L leaching agent, gold concentrate amount 200g/L, add 0.15% gold concentrate amount of sodium lignosulfonate, control oxygen pressure 1.0Mpa, temperature 130°C, react for 2.0 hours, liquid-solid separate.

Pretreatment slag ammonium thiocyanate solution leaching conditions: NH ₄ SCN 2.5mol/L solution, Fe ³⁺ 0.0g/L, pretreatment slag addition 200g/L, add to the reactor and mix with industrial sulfuric acid or lime to adjust pH value to 5.0; control the temperature of the reactor to 130°C, feed oxygen to maintain the pressure in the reactor at 1.2MPa, and react for 4.0 hours; after cooling down, separate solid-liquid and wash, the gold leaching rate is greater than 95%, and the silver leaching rate is greater than 90% . Add iron powder based on 5 times the total amount of gold and silver, replace gold from the leaching solution, stir at 60°C for 30 minutes, the replacement rates of gold and silver are both greater than 99.5%, and return the solution to pressurized oxygen leaching.

Claims (4)

1. Two-stage pressurized oxygen leaching is a method for extracting gold from refractory gold sulfide concentrates, which is characterized in that it adopts two-stage pressurized oxygen leaching, which is divided into pressurized oxygen leaching pretreatment and pressurized oxygen leaching Gold is extracted from refractory gold sulfide concentrates; the first stage of pressurized oxygen leaching pretreatment uses the sulfuric acid-ferric sulfate solution mixed with the first stage filtrate of the first pressurized oxygen leaching pretreatment before the addition of industrial sulfuric acid. agent, and carry out pressure oxidation leaching to obtain the first stage filtrate containing iron and other impurity metals and the pretreatment residue containing elemental sulfur and Au; the second stage pressurized oxygen leaching gold is to use the pretreatment residue to The thiocyanate solution of iron ions is used as the leaching agent for pressurized oxygen leaching, so that gold is selectively dissolved in the form of gold-thiocyanate complex and enters the second stage of filtrate; In the first stage of pressurized oxygen leaching pretreatment process: the leaching agent contains 1-30g/L of iron and ^2-0.5-3mol /L of _SO4 ; the amount of gold concentrate is 80-350g/L, and Zhanjin Sodium lignosulfonate with 0.05-0.5% weight of concentrate, controlled oxygen pressure 0.4-1.8Mpa, temperature 100-180°C, reacted for 0.5-4.0 hours, and separated solid-liquid after cooling down; In the second stage of pressurized oxygen leaching gold leaching process: the leaching agent is 0.05-5.0mol/L containing thiocyanate, 0-10g/L iron ion; the addition amount of gold concentrate pretreatment slag is 80-300g/L L, add to the reaction kettle and adjust the pH value to 1.0-5.0 with industrial sulfuric acid or lime after mixing; control the temperature of the reaction kettle at 100°C-180°C, feed oxygen to maintain the pressure in the reaction kettle at 0.4-2.0MPa, and react for 1.0-6.0 hours ; After cooling down, solid-liquid separation, washing, and gold recovery from the leaching solution, the recovered gold solution is returned to the second stage of pressurized oxygen leaching gold. 2. The method according to claim 1, wherein the refractory gold sulfide concentrate is a gold concentrate containing high arsenic pyrite, antimony sulfide or copper sulfide refractory sulfide. 3. The method according to claim 1, wherein the thiocyanate is ammonium thiocyanate, potassium thiocyanate or sodium thiocyanate, and the thiocyanate concentration is 0.05-5.0mol/L. 4. The method according to claim 1, characterized in that, for the refractory gold sulfide concentrate containing Ca and Mg carbonate ore, it is stirred and decomposed under normal pressure in the reactor to release CO ₂ , and then two stages are carried out. pressurized oxygen immersion.