Method for reducing strong alkalinity of red mud

Abstract

The invention discloses a method for reducing the strong alkalinity of red mud, belongs to the technical field of red mud utilization, and aims to solve the problems that in the prior art, the using amount of an acidic solution for adjusting the alkalinity of red mud is large, the corrosive property of the acidic solution is strong, the cost is high, a large amount of waste liquid, which is hard to process, is generated, and the recovery rate of red mud is low. The method comprises following steps: grinding a biomass raw material by a crusher to obtain biomass powder; delivering biomass powder, water and a catalyst into a stirring pot, stirring to obtain a mixed material; adding the mixed material into a high pressure reactor, heating the high pressure reactor, maintaining the temperature;then cooling to the room temperature to obtain a hydrothermal carbonization product; subjecting the hydrothermal carbonization product to solid-liquid separation to obtain hydrothermal charcoals anda hydrothermal charcoal liquid; mixing the hydrothermal charcoal liquid and red mud, adding the mixture into a stirring tank, stirring, and carrying out solid-liquid separation then to obtain solid modified red mud with reduced alkalinity. The provided method reduces the strong alkalinity of red mud.

Description

technical field [0001] The application relates to the technical field of red mud resource utilization, in particular to a method for reducing the strong alkalinity of red mud. Background technique [0002] Red mud is an industrial solid waste produced in the alumina production process. According to different production processes, red mud is mainly divided into Bayer red mud, sintering red mud and combined red mud. Due to bauxite raw materials, production processes, etc. Due to different factors, there are certain differences in the composition, properties, and phases of the red mud produced; with the continuous growth of alumina production, the global stock of red mud is also rising, and the global red mud discharge has reached 2.6 billion in 2007. Ton. With the continuous growth of the demand for the development of the aluminum industry in China, the output of alumina has also increased rapidly. It is estimated that the discharge of red mud in my country in 2009 has exceed...

AI Technical Summary

Problems solved by technology

Different treatment technologies or methods of red mud must solve the problem of strong alkalinity of red mud. Strong alkalinity is a key issue restricting the comprehensive treatment or resource utilization of red mud. The existing technology generally uses acidic solutions such as hydrochloric acid, sulfuric acid, and nitric acid. Treatment, dealkalization of acidic solution simultaneously destroys the chemical structure of red mud and leaches a large amount of metal elements, resulting in the loss of red mud components; there are problems such as strong corrosion of acidic solution, large amount of waste liquid, and high cost; the generated acidic waste liquid contains a large amount of harmful Metal, hazardous and difficult to handle

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