Method for recycling gold from roasting residues or roasting-leaching residues of gold concentrate

Abstract

A method for recycling gold from roasting residues or roasting-leaching residues of gold concentrate comprises the steps of 1, sulfuric acid curing; 2, extracting the gold from acid leaching residues; and 3, iron precipitation treating of pickle liquor. The step 1 comprises the operation of adding gold-bearing raw material residues into a reactor, then adding water into the reactor, stirring and mixing the residues and the water, then adding sulfuric acid solutions with the mass concentration greater than or equal to 60% into the reactor, stirring the mixtures uniformly, carrying out sealed heat preserving and curing at 80-150 DEG C, adding water for forming slurry, and carrying out stirring, dissolving and washing; the step 2 comprises the operation of adding the water into the acid leaching residues for forming slurry, adjusting the pH value of the slurry to 9-12, pre-treating the slurry for 1-4 hours, adding sodium cyanide for leaching and extracting the gold through activated carbon adsorption; the step 3 comprises the operation of adding water into a reaction container, heating the water to 80-90 DEG C, adding the pickle liquor and iron precipitation agents in the stirring process, strictly controlling the pH value and the Fe<3+> concentration of the liquor and carrying out iron precipitation treatment. The method has the advantages that the process is simple, the operation is convenient, the recovery rate of the gold in the roasting residues can be increased, and the economical and environment-friendly treatment can be realized.

Description

technical field [0001] The invention relates to a method for recovering gold, in particular to a method for recovering gold from gold concentrate roasting slag or roasting-leaching slag. Background technique [0002] The resources of refractory high-sulfur and high-arsenic gold concentrates at home and abroad are relatively abundant, but the gold leaching rate is extremely low when the conventional cyanide gold extraction process is adopted; the two-stage boiling roasting pretreatment technology can improve the leaching rate of such gold ores. be widely used. However, there are also some shortcomings in the production of this process, such as easy to cause overburning, the pores of the calcined sand are closed by iron oxides during overburning, and the gold particles are wrapped twice, resulting in a decrease in the leaching rate of gold; Micro or finer level (less than 0.2um), the secondary wrapping phenomenon is more serious. Generally, the leaching rate of gold from roa...

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Problems solved by technology

However, there are also some shortcomings in the production of this process, such as easy to cause overburning, the pores of the calcined sand are closed by iron oxides during overburning, and the gold particles are wrapped twice, resulting in a decrease in the leaching rate of gold; Micro or finer level (less than 0.2um), the secondary wrapping phenomenon is more serious

Generally, the leaching rate of gold from roasted refractory gold concentrate is lower than 86%. The higher the arsenic content, the lower the leaching rate of roasting slag, and the finer the gold particle size, the lower the leaching rate of roasting slag. Less than 50%, the gold grade of the cyanide leaching residue is as high as 15g / t or more, which cannot be recovered, resulting in a large amount of waste of gold

[0003] At present, there is a molten pool smelting method in the lead and copper smelting industry, and the roasting and leaching slag is added to the molten pool as a slagging agent. Through the process of smelting lead and copper, precious metals such as gold enter the crude lead and copper to realize the recovery of gold. Recycling, iron, etc. enters the metallurgical slag, and its disadvantages are: a. It needs to build a series of equipment for pyrometallurgy of lead and copper, which is high in construction cost and high in operation cost; Difficult to process, high environmental pressure; C, iron and other elements cannot be recovered and enter the smelting slag, low added value, high yield of slag, difficult to resource treatment

[0004] CN102719678A discloses a pretreatment method for high-sulfur and high-arsenic refractory gold concentrate roasting slag. This method uses sulfuric acid and chloride as leaching agents for high-temperature aging to achieve the purpose of opening the wrapped gold. The disadvantages are: a. Chlorides are very corrosive to equipment, and expensive materials need to be used for anti-corrosion treatment, which greatly increases equipment investment; b, chlorides are prone to produce volatile HCl gas in a high-acid, high-temperature environment, and have a high risk of polluting the surrounding environment; c, It needs to use a high temperature of up to 400 degrees Celsius, which consumes a lot of heat and energy for the treatment of water-containing cyanide leaching slag; d. Only the recovery of gold is explained, and the subsequent filtrate (such as wastewater containing iron and acid, etc.) Proposal for environmental protection

The disadvantages are: a. The main purpose is to extract iron and lead, and sulfuric acid is used as 98% sulfuric acid, and the curing time is long (2-5 hours); b. It takes a long time after curing (4-6 hours), and it is relatively Acid leaching with high acidity (25-35% sulfuric acid concentration) and higher temperature (60-110°C) can achieve the goal, and the process is complicated; c. The iron product is iron oxide red, the product is single, the social demand is limited, and Fire calcination is required, which is not enough to deal with a large amount of waste residue

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