CN1932051A

CN1932051A - Wet gold purifying process

Info

Publication number: CN1932051A
Application number: CNA2005100180005A
Authority: CN
Inventors: 王安理; 范尚立; 赵金宁
Original assignee: JINYUAN TONGHUI REFINING CO Ltd LINGBAO
Current assignee: JINYUAN TONGHUI REFINING CO Ltd LINGBAO
Priority date: 2005-09-15
Filing date: 2005-09-15
Publication date: 2007-03-21
Anticipated expiration: 2025-09-15
Also published as: CN100386454C

Abstract

The present invention relates to wet gold purifying process, which includes the steps of powdering gold containing material; chloridizing leaching; and reducing under controlled potential. Through the reducing under controlled potential, the gold ingot can reach the requirement of national standard without need of further depurating. The present invention has high once gold reducing rate up to 97 %, processing loss lower then 0.15 %, lower gold retaining amount, simple operation and other advantages.

Description

Wet gold purification process

Technical Field

The invention relates to a gold purificationprocess, in particular to a gold wet purification process.

Background

At present, the gold refining and purifying method at home and abroad mainly comprises the following steps: the method comprises the steps of (1) a liquid chlorine method, an electrolysis method, a chlorination method and a chlorine-ammonia purification method, wherein the liquid chlorine method mainly comprises the steps of introducing chlorine as an oxidant, wherein in the working process, the introduced chlorine is little and does not bubble, the oxidation is not thorough, the recovery rate is influenced, and when the introduced chlorine is much, the chlorine is easy to escape and harmful to human bodies; the electrolytic method has simple flow and less pollution, but the technical condition of the electrolytic method has high requirement and needs to accumulate a large amount of gold, thereby bringing certain difficulty to mine turnover and safety protection work; the method adopts chemical reagents to carry out impurity removal and purification treatment, and has the advantages of complex process, long production period and large occupied capital.

Disclosure of Invention

In view of the above problems, the present invention provides a gold wet purification process to simplify the purification process, shorten the production cycle, and reduce the investment.

In order to achieve the purpose, the technical scheme of the invention is that a gold wet purification process is adopted, and the gold wet purification process comprises the following steps: (1) pulverizing the alloy gold; (2) chloridizing and leaching, namely adding the pulverized gold alloy powder into a reaction kettle, and adding HCL; starting the stirring system, slowly adding HNO₃(ii) a Closing the feed inlet of the reaction kettle, and heating to 80-90 ℃; after 5-7 hours, observing that no yellow smoke is emitted from the reaction kettle, and putting the solution into a filter vat; washing the filter residue with hot water, putting the washing water into a filter barrel, and melting and reducing the filter residue into silver; (3) controlling potential reduction, pumping the chlorination leaching solution into a primary reduction reaction kettle from a filter barrel, adding NaOH with the concentration of 2096, and adjusting the pH value to be 1-1.5; adding anhydrous Na in batches₂SO₃Stirring, and controlling the potential to be more than 750 mv; when the electrode potential is lower than 750mv, putting the materials in the reaction kettle into a filter vat; the material on the filter cloth is gold powder, the gold powder is cleaned by hot water, diluted nitric acid is added for boiling for 1 to 2 hours, and the gold powder is cleaned, dried and sent to be melted and cast into finished ingots; pumping the filtrate to a secondary reduction kettle; adding excessive anhydrous Na into a secondary reduction kettle₂SO₃Stirring for 1 hour, and putting the materials in the reaction kettle into a filter barrel; the materials on the filter cloth are secondary reduced gold powder, and the materials are cleaned by hot water and returned to the chlorination leaching process; pumping the filtrate to a reduction tank, adding a small amount of zinc wires for reduction, and testing to discharge after reaching the standard; soaking the obtained zinc wire in dilute hydrochloric acid for half an hour, cleaning with hot water, and returning to the chlorination leaching process.

The alloy powder is prepared fromThe method comprises the following steps: weighing, preparing the plate, electrolyzing in low color, and washing the anode mud with nitric acid, wherein the plate components (30 percent, and the current density is 1200A/m)²Circulation velocity of electrolyte solution 4m³/h。

The dosage of the acid is (weight ratio): au: HNO₃∶HCL＝0.8-1∶0.5-0.6∶2.2-2.6。

The reaction mechanism of the invention is as follows:

the process of the invention can meet the requirements of national standard gold ingots by controlling the reduction potential without further impurity removal treatment. In addition, the process can omit pulverization equipment, so that the efficiency is improved; the reduction rate of the primary gold is high and can reach more than 97 percent; the processing loss is small and is less than 1.5 per mill; the quantity of the gold stored in the process is small, the process reserve is not more than 20kg and is far lower than the stock of 200kg in the process of the electrolytic method; the occupied pressure capital is small, and the metal balance work is easy to be carried out; the process adopts control potential reduction, is simple and convenient to operate, easy to realize automatic control, low in labor intensity, easy to control impurities, stable in quality and high in purity, and the product is subjected to multiple sampling inspection by units such as the inspection center of gold and silver products of great wall of Sichuan gold and silver refineries, Shenyang coinage technical research institute and the like, so that the gold and silver products all reach the national standard; the invention has the advantages of less project investment, quick effect, mature technology and is most suitable for being popularized to middle and small-sized gold smelting; the principle that the environment protection and the production construction are designed simultaneously, constructed simultaneously and put into production simultaneously is adhered to in the implementation process of the project, and the project passes the environment protection acceptance.

Drawings

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

As shown in figure 1, the gold wet purification process of the invention comprises the following steps: (1) powdering the alloy gold, weighing, preparing plate, low-color electrolyzing, and washing with nitric acidAnode mud, wherein the gold content of the plate component (30 percent, the current density is 1200A/m)²Circulation velocity of electrolyte solution 4m³H; (2) chloridizing and leaching, namely adding the pulverized gold alloy powder into a reaction kettle, and adding HCL; starting the stirring system, slowly adding HNO₃Paying attention to the condition in the reaction kettle to prevent overflowing; closing a feed inlet of the reaction kettle, and heating to 85 ℃; after 6 hours, observing that no yellow smoke is emitted from the reaction kettle, and putting the solution into a filter vat; washing the filter residue with hot water, putting the washing water into a filter barrel, and melting and reducing the filter residue into silver; (3) controlling potential reduction, pumping the chlorination leaching solution into a primary reduction reaction kettle from a filter vat, adding 20% NaOH, and adjusting the pH value to 1.5; adding anhydrous Na in batches according to the reaction proportion₂SO₃Stirring, and controlling the potential to be more than 750 mv; when the electrode potential is lower than 750mv, stopping adding the reducing agent, and putting the materials in the reaction kettle into a filter vat;the material on the filter cloth is gold powder, the gold powder is cleaned by hot water, diluted nitric acid is added for boiling for 1.5 hours, and the gold powder is cleaned, dried and sent to be melted and cast into finished ingots; pumping the filtrate to a secondary reduction kettle; adding excessive anhydrous Na into a secondary reduction kettle₂SO₃Stirring for 1 hour, and putting the materials in the reaction kettle into a filter barrel; the materials on the filter cloth are secondary reduced gold powder, and the materials are cleaned by hot water and returned to the chlorination leaching process; pumping the filtrate to a reduction tank, adding a small amount of zinc wires for reduction, and testing to discharge after reaching the standard; soaking the obtained zinc wire in dilute hydrochloric acid for half an hour, cleaning with hot water, and returning to the chlorination leaching process. Wherein the dosage of the gold and the acid is (weight ratio): au: HNO₃∶HCL＝1∶0.6∶2.5。

Claims

1. A gold wet purification process is characterized in that: the method comprises the following steps: (1) pulverizing the alloy gold; (2) chloridizing and leaching, namely adding the pulverized gold alloy powder into a reaction kettle, and adding HCL; starting the stirring system, slowly adding HNO₃(ii) a Closing the feed inlet of the reaction kettle, and heating to 80-90 ℃; after 5-7 hours, observing that no yellow smoke is emitted from the reaction kettle, and putting the solution into a filter vat; washing the residue with hot water, adding the water to a filter vat, melting the residueReducing the silver to silver; (3) controlling potential reduction, pumping the chlorination leaching solution into a primary reduction reaction kettle from a filter vat, adding 20% NaOH, and adjusting the pH value to be 1-1.5; adding anhydrous Na in batches₂SO₃Stirring, and controlling the potential to be more than 750 mv; when the electrode potential is lower than 750mv, putting the materials in the reaction kettle into a filter vat; the material on the filter cloth is gold powder, the gold powder is cleaned by hot water, diluted nitric acid is added for boiling for 1 to 2 hours, and the gold powder is cleaned, dried and sent to be melted and cast into finished ingots; pumping the filtrate to a secondary reduction kettle; adding excessive anhydrous Na into a secondary reduction kettle₂SO₃Stirring for 1 hour, and putting the materials in the reaction kettle into a filter barrel; the materials on the filter cloth are secondary reduced gold powder, and the materials are cleaned by hot water and returned to the chlorination leaching process; pumping the filtrate to a reduction tank, adding a small amount of zinc wires for reduction, and testing to discharge after reaching the standard; soaking the obtained zinc wire in dilute hydrochloric acid for half an hour, cleaning with hot water, and returning to the chlorination leaching process.

2. The wet purification process of gold according to claim 1, wherein: the pulverization of the alloy is as follows: weighing, preparing plate, low-color electrolysis, and washing anode mud with nitric acid, wherein the plate component is less than 30%, and the current density is 1200A/m²Circulation velocity of electrolyte solution 4m³/h。

3. The wet purification process of gold according to claim 1, wherein: the dosage of the acid is (weight ratio): au: HNO₃∶HCL＝0.8-1∶0.5-0.6∶2.2-2.6。