Red mud resource utilization method

Abstract

A red mud resource utilization method includes the steps: mixing red mud with diluted sulfuric acid solution with the concentration of 10-30% according to the weight ratio of 1:2-1:6, and stirring the mixture to slurry; adding, by mass, 5-65% of solution containing NO2<-1> or NO3<-1>, stirring the mixture in a reaction kettle and heating to 40-100 DEG C prior to leaching for 0.5-5 hours, wherein the weight ratio of the solution to the diluted sulfuric acid solution with the concentration of 10-30% is 0.1-1:100; filtering residues out to obtain filtrate, and analyzing the iron content in the filtrate; adding ferrous sulfate into the filtrate, increasing the temperature to 40-100 DEG C after stirring and dissolution, and feeding oxygen or compressed air for reaction for 1-10 hours, wherein the weight ratio of the ferrous sulfate to iron in the filtrate is 1-25:100; and ageing for 5-50 hours to obtain a silicon, iron and aluminum ternary composite water purifying agent finished product. Leaching amount of the silicon, the iron and the aluminum in the red mud can be increased by performing acid leaching for the red mud by the aid of the diluted sulfuric acid solution and the solution containing the NO2<-1> or the NO3<-1>. Besides, the added ferrous sulfate solution and the solution containing the NO2<-1> or the NO3<-1> are capable of promoting polymerization of the silicon, the iron and the aluminum in leaching liquor, and an obtained ternary composite water purifying agent is good in water purification performance.

Description

technical field [0001] The invention relates to the technical field of resource utilization of red mud from industrial waste, in particular to a method for resource utilization of red mud. Background technique [0002] Red mud is the industrial solid waste that is discharged after refining alumina from bauxite. Generally, for every ton of alumina produced, 1.0 to 2.0 tons of red mud is incidentally produced. As the fourth largest producer of alumina in the world, my country produces more than 30 million tons of red mud every year. A large amount of red mud cannot be fully and effectively utilized and can only be stacked in large-scale storage yards. On the one hand, the storage of red mud requires a certain amount of capital construction costs, occupies a large amount of land, and makes many available components in the red mud not be used rationally, resulting in a waste of resources; Its chemical components penetrate into the land and easily cause land and groundwater poll...

AI Technical Summary

Problems solved by technology

Red mud is used to prepare building materials, ceramics or ceramsite, which is of low value and is affected by transportation costs. The market is limited to local areas and the consumption is limited; recycling alkali can reduce the alkali pollution of red mud to the environment and improve the resource utilization of red mud Utilization does not contribute much; the current technology for recycling iron and rare earths is not yet mature, the recovery rate is low, and the cost is high, so it is difficult to promote large-scale industrialization

However, there are two deficiencies in the prior art of using red mud as a raw material to prepare ternary composite water purifying agent polysilicate iron and aluminum: one is that the silicic acid in the product is additionally added, and the silicon in red mud itself is not utilized; The second is that the iron in the red mud is already trivalent iron, and the aggregation of iron is limited

Images