CN114790512A

CN114790512A - Method for enriching precious metals in electric furnace materials

Info

Publication number: CN114790512A
Application number: CN202210437644.1A
Authority: CN
Inventors: 潘从明; 张燕; 杨丽虹; 杨万虎; 杜彦君; 高向乾; 韩彬; 刘成
Original assignee: Jinchuan Group Co Ltd
Current assignee: Jinchuan Group Co Ltd
Priority date: 2022-04-25
Filing date: 2022-04-25
Publication date: 2022-07-26

Abstract

The invention discloses a method for enriching noble metals, in particular to a method for enriching noble metals in electric furnace materials; the method specifically comprises the following steps: (1) leaching the electric furnace materials for 8-12 hours at 55-95 ℃ by using a hydrochloric acid solution with the volume fraction of 5-15%, wherein hydroxylamine hydrochloride with the mass of 1-5% of the materials is added into the hydrochloric acid solution, and filtering after leaching; (2) dissolving the filter residue to form a solution, controlling the pH of the solution to be =0-2, adding vitamin C which is 2-5 times of the mass of the gold, silver, platinum and palladium in the solution, reacting at 60-65 ℃ for 1-2 hours, filtering, and separating and refining the gold, silver, platinum and palladium in the filter residue; (3) heating the filtrate to 70-90 ℃, adding sodium hydroxide or potassium hydroxide to adjust the pH value to be more than or equal to 14, introducing chlorine gas into the filtrate until the pH value is more than or equal to 5-9 until the content of rhodium and iridium in the treated liquid is less than or equal to 0.001g/L, filtering, discharging the filtrate, and recovering rhodium and iridium from filter residues. The method has the advantages of simple process flow and small difficulty in field operation, and solves the problem of long process for enriching the precious metals from low-grade materials.

Description

Method for enriching precious metals in electric furnace materials

Technical Field

The invention belongs to the field of precious metal metallurgy, and particularly relates to a method for enriching precious metals in iron-precious metal alloy obtained by smelting and enriching in an electric arc furnace, which is particularly suitable for smelting and trapping iron-precious metal alloy produced by self-producing low-grade precious metal materials in the smelting process of the precious metals in the electric arc furnace.

Technical Field

The pyrometallurgical fusion iron-capturing method is one of important recovery methods for recovering platinum group metals from spent automobile exhaust catalysts and other platinum group metal catalysts, and mainly comprises electric arc furnace smelting and plasma furnace smelting enrichment, and the two methods are both suitable for low-grade precious metal materials. The low-grade precious metal materials mainly comprise two main types, namely secondary resource materials represented by waste automobile exhaust catalysts and petroleum catalysts; secondly, the self-production low-grade (less than or equal to 300 g/t) complex precious metal materials represented by waste water neutralization materials, chlorinated insoluble materials and the like in the precious metal smelting process. The two materials adopt a plasma smelting furnace and an electric arc smelting furnace, iron, copper and high nickel matte are used as collecting agents to enrich precious metals in the materials, and corresponding iron (copper and nickel) -precious metal alloys are produced.

The alloy material usually contains about 1-15% of noble metal and more than 80% of impurity elements such as iron (copper, nickel) and the like, wherein the iron-noble metal alloy usually adopts dilute sulphuric acid or dilute hydrochloric acid to leach impurity iron to achieve the purpose of primarily enriching noble metal, leaching residues are chloridized and dissolved, a copper powder displacement process is adopted to enrich gold, silver, platinum and palladium in the leaching residues, and zinc and magnesium powder is adopted to displace, enrich and recover rhodium and iridium in the leaching residues. The process has the following problems: (1) about 0.X-0.0Xg/L of noble metal in the dilute acid leaching solution is difficult to recover due to the interference of impurity iron; (2) impurity copper is introduced in the process of enriching gold, silver, platinum and palladium by a copper powder replacement process, so that the subsequent separation and refining of precious metals are interfered; (3) although the zinc magnesium powder replaces the rhodium iridium to realize the enrichment of the rhodium iridium, the impurities of zinc and magnesium are difficult to remove, and the extraction flow of the rhodium iridium is long. A new method of iron-precious metal alloy is needed to solve the above problems.

Disclosure of Invention

The invention provides a method for enriching precious metals in electric furnace materials, which aims to solve the technical problem of efficiently enriching the precious metals.

The invention relates to a method for enriching precious metals in electric furnace materials, which solves the technical problem by the following scheme:

(1) smelting and trapping iron-precious metal alloy produced in the precious metal smelting process by an electric arc furnace, leaching for 8-12 hours at 55-95 ℃ by using a hydrochloric acid solution with the volume fraction of 5-15%, wherein hydroxylamine hydrochloride with the mass of 1-5% of the material is added into the hydrochloric acid solution, filtering after leaching, and treating the filtrate in a wastewater treatment station;

(2) dissolving the filter residue to form a solution, controlling the pH of the solution to be =0-2, adding vitamin C which is 2-5 times of the mass of the gold, silver, platinum and palladium in the solution, reacting for 1-2 hours at 60-65 ℃, filtering, and separating and refining the gold, silver, platinum and palladium in the filter residue.

(3) Heating the filtrate to 70-90 ℃, adding sodium hydroxide or potassium hydroxide to adjust the pH value to be more than or equal to 14, introducing chlorine gas into the filtrate until the pH value is =5-9 until the content of rhodium and iridium in the treated liquid is less than or equal to 0.001g/L, filtering, discharging the filtrate, and recovering rhodium and iridium from filter residues.

Compared with the prior art, the invention has the following beneficial effects:

1. the method for enriching the precious metals in the electric furnace materials is simple in process flow, economical, environment-friendly, convenient and effective.

2. According to the method for enriching the precious metals in the electric furnace materials, the vitamin C which is relatively clean and environment-friendly is adopted to realize the high-efficiency separation of the gold, the silver, the platinum and the palladium from the rhodium and the iridium, and the total content of the gold, the platinum and the palladium in the precipitate can reach more than 30%.

3. According to the method for enriching the precious metals in the electric furnace materials, hydroxylamine hydrochloride added in the hydrochloric acid leaching process can inhibit trace leaching of the precious metals while ensuring iron leaching, and the content of the precious metals in the leached liquid is less than or equal to 0.001 g/L.

Drawings

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

Detailed Description

The present invention will be further described with reference to the following examples.

Example 1

(1) Smelting and trapping iron-precious metal alloy (the total content of precious metal is 2.2%) produced in the precious metal smelting process by using an arc furnace of 100g, leaching for 8 hours at 5 ℃ by using hydrochloric acid solution with the volume fraction of 5%, wherein 1g of hydroxylamine hydrochloride is added into the hydrochloric acid solution, filtering is carried out after leaching to obtain filter residue, the content of the precious metal in the filtrate is less than or equal to 0.0005g/L, and the filtrate enters a wastewater treatment station for treatment;

(2) dissolving the filter residue obtained in the step (1) to make a solution, controlling the pH =0 of the solution, adding vitamin C which is 2 times of the mass of the gold, silver, platinum and palladium in the solution, reacting at 60 ℃ for 1 hour, filtering, and separating and refining the gold, silver, platinum and palladium (the total content is 40.26%) in the filter residue;

(3) heating the filtrate obtained in the step (2) to 70 ℃, adding sodium hydroxide or potassium hydroxide to adjust the pH value to be more than or equal to 14, introducing chlorine gas into the filtrate until the pH value is =5 until the content of rhodium and iridium in the treated liquid is less than or equal to 0.001g/L, filtering, discharging the filtrate, and recovering rhodium and iridium from filter residues.

Example 2

(1) Smelting and trapping iron-precious metal alloy (the total content of precious metals is 1.3%) produced in the precious metal smelting process by using 1000g of an electric arc furnace, leaching for 12 hours at 95 ℃ by using hydrochloric acid solution with the volume fraction of 15%, wherein 50g of hydroxylamine hydrochloride is contained in the hydrochloric acid solution, filtering to obtain filter residues after leaching, the content of the precious metals in the filtrate is less than or equal to 0.0002g/L, and treating the filtrate in a wastewater treatment station;

(2) dissolving the filter residue obtained in the step (1) to form a solution, controlling the pH =2 of the solution, adding vitamin C which is 5 times of the mass of the gold, silver, platinum and palladium in the solution, reacting for 2 hours at 65 ℃, filtering, and separating and refining the gold, silver, platinum and palladium (the total content is 35.07%) in the filter residue;

(3) heating the filtrate obtained in the step (2) to 90 ℃, adding sodium hydroxide or potassium hydroxide to adjust the pH value to be more than or equal to 14, introducing chlorine gas into the filtrate until the pH value is =9 until the content of rhodium and iridium in the treated liquid is less than or equal to 0.001g/L, filtering, discharging the filtrate, and recovering rhodium and iridium from filter residues.

Example 3

(1) Leaching 100kg of iron-precious metal alloy (the total content of precious metals is 1.08%) produced in the smelting process of smelting and trapping precious metals in an electric arc furnace by using 10 volume percent hydrochloric acid solution at 80 ℃ for 10 hours, wherein 1kg of hydroxylamine hydrochloride is contained in the hydrochloric acid solution, filtering is carried out after leaching to obtain filter residues, the content of the precious metals in the filtrate is less than or equal to 0.0008g/L, and the filtrate enters a wastewater treatment station for treatment;

(2) dissolving the filter residue obtained in the step (1) to prepare a solution, controlling the pH =1 of the solution, adding vitamin C which is 3 times of the mass of the gold, silver, platinum and palladium in the solution, reacting at 62 ℃ for 1.5 hours, filtering, and separating and refining the gold, silver, platinum and palladium (the total content is 32.11%) in the filter residue;

(3) heating the filtrate to 90 ℃, adding sodium hydroxide or potassium hydroxide to adjust the pH value to be more than or equal to 14, introducing chlorine gas into the filtrate until the pH value is =9 until the rhodium-iridium content in the treated liquid is less than or equal to 0.001g/L, filtering, discharging the filtrate, and recovering the rhodium-iridium from the filter residue.

Claims

1. A method for enriching precious metals in electric furnace materials is characterized by comprising the following steps:

(1) smelting and trapping iron-precious metal alloy produced in the precious metal smelting process in an electric arc furnace, leaching for 8-12 hours at 55-95 ℃ by using hydrochloric acid solution with the volume fraction of 5-15%, wherein hydroxylamine hydrochloride with the mass of 1% -5% of that of the iron-precious metal alloy is added into the hydrochloric acid solution, filtering after leaching to obtain filter residue, and treating the filter residue in a waste water treatment station;

(2) dissolving the filter residue obtained in the step (1) to prepare a solution, controlling the pH =0-2 of the solution, adding vitamin C which is 2-5 times of the mass of the gold, silver, platinum and palladium in the solution, reacting at 60-65 ℃ for 1-2 hours, filtering to obtain a filtrate, and separating and refining the gold, silver, platinum and palladium in the filter residue;

(3) heating the filtrate obtained in the step (2) to 70-90 ℃, adding sodium hydroxide or potassium hydroxide to adjust the pH value to be more than or equal to 14, introducing chlorine gas into the filtrate until the pH value is =5-9 until the content of rhodium and iridium in the treated liquid is less than or equal to 0.001g/L, filtering, discharging the filtrate, and recovering rhodium and iridium from filter residues.