Method for recycling industrial waste sulfate slag

Abstract

The invention provides a method for recycling industrial waste sulfate slag, which comprises the steps of sieving, stirring, magnetic separation, acid dipping, rinsing and drying to obtain iron-bearing materials. The method not only reallocates the available resource of the sulfate slag which is difficult to be processed and has high pollution, but also reduces the severe contamination of the sulfate slag to the environment and simultaneously lowers the production cost greatly; the metal recovery rate is 50 to 82 percent, high quality iron concentrate with the grade of iron being larger than 60 percent, the grade of sulfur being smaller than 0.3 percent and the grade of arsenic being smaller than 0.1 percent is obtained; simultaneously the recovery processing capacity is large, the equipment is simple, the investment is small, the operation is convenient, the sulfate slag material is not limited, both the sulfate slag with high iron content and the sulfate slag with low iron content can be recycled, and the method has good social benefit and remarkable economic effect.

Description

technical field [0001] The invention relates to a method for recovering and treating sulfuric acid slag, in particular to a method for recycling and treating sulfuric acid slag by using industrial waste acid, and belongs to the technical field of industrial waste slag treatment and recovery. Background technique [0002] In the process of producing sulfuric acid from pyrite in my country, about 70 million tons of sulfuric acid slag are discharged every year, accounting for one-third of the total waste in the chemical industry. Due to the large amount of slag, fine particle size, flying all over the sky in sunny days, red water flow in rainy days, and high content of harmful impurities such as sulfur and arsenic, it has caused incalculable harm to the environment. At present, except for the sulfuric acid slag with high iron content that can be recycled and treated, most of the sulfuric acid slag with low or low iron content cannot be disposed of, but landfilled. Over time, it...

AI Technical Summary

Problems solved by technology

But the deficiencies in this process are: (1) After the sulfuric acid slag is processed through grinding, although it is beneficial to acid leaching, it has changed the original phase of the sulfuric acid slag because of the grinding process, making it difficult to use the subsequent magnetic Sorting or flotation, which fundamentally restricts the improvement of iron grade; meanwhile, the investment in grinding equipment is large, and the power consumption is high (based on the daily processing capacity of 200 tons / day, the power consumption is about 50KW), and the processing cost is high.

(2) Since the grinding is directly carried out into the acid leaching treatment, the whole processing production line is completely in the acid environment. First, the production equipment and site are severely corroded, and the loss of equipment is increased, resulting in high production costs. Second, the harsh production environment is also serious. It threatens the health of on-site workers. Third, a large amount of pulp needs to consume a large amount of acid to complete acid leaching, which not only increases production costs, but also increases acid pollution.

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