Harm-free and recycling treatment method for chromium slag

Abstract

The invention provides a harm-free and recycling treatment method for chromium slag. In the method, after being made into dried particles with the grain diameter of 0.5-10mm, the chromium slag is mixed with tapped melting converter steel slag; the addition amount of the chromium slag is 0.5-5 percent of the weight of the melting converter steel slag; after the chromium slag is mixed with the melting converter steel slag, the mixture carries out melting reaction for 1-8 minutes. The method has simple procedure and processes the chromium slag directly by the melting converter steel slag without consuming an external energy source; and the processed chromium slag is melted into the converter steel slag and comprehensively utilized according to a utilization approach of the converter steel slag, thereby realizing the safe recycling utilization of the chromium slag.

Description

technical field [0001] The invention relates to the technical field of solid waste treatment, in particular to a method for treating chromium slag by using high-temperature molten converter steel slag, thereby realizing harmless and resourceful chromium slag. Background technique [0002] Chromium slag is a waste residue containing hexavalent chromium produced in the process of producing chromium salt with calcium roasting process. As a toxic solid waste, chromium slag not only endangers people's health, but also causes serious pollution to the ecological environment. Chromium slag contains Cr 2 o 3 and toxic Cr 6+ (including water-soluble sodium chromate Na 2 CrO 4 and acid-soluble calcium chromate CaCrO 4 , with Na 2 CrO 4 In addition, it also contains a large amount of oxides of calcium, magnesium, aluminum, and silicon, which have certain utilization value. Therefore, the harmless treatment and resource utilization of chromium slag are effective ways to realize th...

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Problems solved by technology

However, this method needs to heat the metallurgical slag used to 1200-1450°C, and the heating and heat preservation of the slag need to consume extra energy, which is high energy consumption; this method uses the residual carbon in blast furnace slag, electric furnace slag, and blast furnace slag to reduce and detoxify chromium slag, but the residual carbon content in the above three slags is generally less than 0.2%, the carbon content of the reducing agent is low, and the reduction and detoxification effect of the chromium slag cannot be guaranteed; in addition, the added chromium slag powder is required to pass through a 20-mesh sieve, and the particle size is relatively fine , it is easy to produce chromium slag dust pollution during on-site operation; the slag is cooled to room temperature by natural cooling after the reduction reaction in this method. The fixation effect of the chromium contained in it is poor, and there is a risk of secondary dissolution of trivalent chromium and hexavalent chromium; and now the treatment of blast furnace slag is a streamlined operation, and it is directly water-quenched and cooled after it comes out of the slag ditch of the casting plant Afterwards, this method requires special equipment to transfer the blast furnace slag to the slag tank, which is inconvenient to operate

[0007] There are many harmless treatment technologies for chromium slag. If the comprehensive utilization of chromium slag is to be realized at the same time, most of the existing technologies have problems of incomplete detoxification, complicated process, small amount of slag eaten, high treatment cost, and processed chromium slag or its products. Disadvantages such as difficulty in reuse make it difficult for existing harmless treatment technologies to be widely applied

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