Method and system for extracting gold from arsenic contained headings

Abstract

A process for extracting gold from the As-contained gold ore concentrate includes such steps as heating the smelting chamber to 100-300 deg.C, holding the temp for removing the water vapour and dust, heating the smelting chamber and crystallizing chamber to 300-500 deg.C, holding the temp for removing the volatile sulfide of As, heating the smelting chamber to 500-600 deg.C while holding the temp of crystallizing temp for removing the gas-phase sulfur, heating smelting chamber to 600-760 deg.C while cooling crystallizing chamber to 270-370 deg.C to obtain As, cooling while aerating to obtain the gold-enriched dregs, and conventional extracting of pure gold. Its equipment is also disclosed.

Description

technical field [0001] The present invention relates to a method for extracting gold from arsenic-containing gold concentrate, in particular to a method for extracting fine-grained gold from arsenic-containing gold sulfide concentrate; A system for extracting gold from a mine. Background technique [0002] To extract gold from minerals, especially the microparticle and submicroparticle gold wrapped in sulfide minerals such as pyrite and arsenopyrete, the arsenic in these minerals must first be completely removed in order to effectively extract gold. How to completely remove the arsenic in the gold concentrate without polluting the environment has always been a major technical difficulty in gold production, and this difficulty has always restricted the output of gold. [0003] The conventional arsenic removal method is to oxidize and roast arsenic-containing gold concentrate or arsenopyrite ore, so that the arsenic in the mineral is oxidized to As 2 o 3 Volatilize to achie...

AI Technical Summary

Problems solved by technology

Although this method is relatively simple, it has four major disadvantages: (1) During the roasting process, due to part of the arsenic and gold at the roasting temperature, at about 900 ° C, a low-boiling arsenic-gold compound is volatilized. , thus greatly reducing the recovery rate of gold

(2) Qualified arsenic products cannot be obtained

During roasting, impurity metals such as Sb, Bi, Pb, Hg, Zn in minerals also combine with As in the form of oxides. 2 o 3 Volatile together, and mixed together, As 2 o 3 The purity of the product cannot meet the requirements of its product and cannot be sold

In order to make As 2 o 3 The by-products are utilized, and the conventional method is to convert As 2 o 3 Put it into the atmospheric pressure electric heating vertical tank reduction furnace, use carbon to convert As 2 o 3 Reduction to elemental arsenic is labor intensive

(3) Whether it is the oxidative calcination process or As 2 o 3 The process of reducing to the element As must be combined with the giant poison As 2 o 3 In dealing with each other, it is difficult to avoid As 2 o 3 pollution to the environment

Especially the personal safety of the operator is more difficult to guarantee

(4) Arsenic cannot be completely removed

However, there are still many problems in the experimental results: (1) the grade of arsenic does not meet the international requirement of 99% arsenic, and can only reach 76-92% of crude arsenic. Even if it is distilled again, it is difficult to meet the product requirements, and the cost is very high

(2) Since the smelting temperature is as high as 1100-1200°C and the material is in a semi-melted state, it is difficult to discharge slag when it is applied to industrial production

(3) The exhaust problem cannot be solved

When arsenic vapor and water vapor are generated in the furnace, the smelted material is splashed and a large amount of dust is generated to pollute the arsenic product, and qualified arsenic cannot be obtained.

(4) The arsenic content in slag is as high as 10-18%, not only the recovery rate of arsenic is low, but also there is still the problem of requiring arsenic removal in the subsequent smelting process

[0005] Another example is the existing horizontal rotary vacuum furnace, which extracts elemental arsenic from arsenopyrite ore and has done small and medium-sized experiments, but there are many problems, and it cannot be used for industrial production until now. The main problems are as follows: (1) the arsenic in the rotating furnace body The corrosion problem has not been solved, the life of the furnace is very low, and it cannot be adapted to industrial production

(2) Due to the rotation of the furnace body, a large amount of dust is generated during the process of forcing the material to be turned continuously, which seriously pollutes the product. This is its second fatal weakness

(3) The exhaust problem cannot be solved

The water vapor generated by the crystalline water in the material at high temperature directly enters the vacuum unit, often making the vacuum pump unable to operate normally, and often causing the vacuum solenoid valve to fail, and the vacuum degree cannot be guaranteed. Rust makes the vacuum pump useless

These accidents often lead to air leakage in the vacuum system and cause As 2 o 3 pollution

(4) Since the furnace shell is constantly rotating, it is very difficult to measure the real temperature inside the rotating body

In addition, this type of furnace sets the melting chamber and the crystallization chamber in the same furnace shell, and the temperature at the junction of the two chambers is more difficult to control.

(5) The slag discharge and stripping of the product cannot be carried out at the same time, but the product must be stripped first and then the slag is discharged, which greatly prolongs the operation time

However, the micro-negative pressure test can only prove that the thermal decomposition of arsenopyrite ore to separate the element arsenic is true, but cannot eliminate As 2 o 3 The resulting conditions are still far from industrial production

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