Method for efficient and comprehensive utilization of high-iron bauxite

Abstract

The invention relates to a method for efficient and comprehensive utilization of high-iron bauxite. The method provided by the invention comprises the following steps that 1, high-iron bauxite and hydrochloric acid are mixed, then are added into a hydrochloric acid-resistant medium-pressure reactor and undergo a heating reaction; 2, after cooling, the reaction products are subjected to solid-liquid separation so that high-silicon dregs and a solution containing aluminum chloride and ferric chloride are obtained; 3, the solution containing aluminum chloride and ferric chloride is added with an excess amount of a sodium hydroxide alkaline solution so that a sodium aluminate solution and high-iron dregs are obtained; and the sodium aluminate solution is electrolyzed to produce chlorine, hydrogen, a sodium hydroxide solution and a pure sodium aluminate solution; 4, the pure sodium aluminate solution is introduced into a crystal seed precipitation tank, is subjected to precipitation and then is subjected to solid-liquid separation so that aluminum hydroxide products and a mother liquor are obtained by the precipitation; and 5, the aluminum hydroxide products are graded, wherein the aluminum hydroxide products having small granularity are utilized as crystal seeds for precipitation and the aluminum hydroxide products having big granularity are washed and then are subjected to high-temperature calcination to form metallurgical-grade alumina products. The method provided by the invention can realize effective precipitation of alumina and iron of high-iron bauxite, has low energy consumption in a whole flow, avoids waste production, realizes full green production and is conducive to industrialization.

Description

technical field [0001] The invention relates to a method for comprehensive utilization of bauxite, in particular to a method for comprehensive utilization of high-iron bauxite with high efficiency. Background technique [0002] Over the years, with the rapid development of the national economy, my country's iron and steel industry and alumina industry have achieved unprecedented development and become the world's largest producer of steel and alumina. However, due to resource shortages, my country's iron ore relies heavily on foreign imports. There is no right to speak in iron ore pricing, which restricts the further development of my country's iron and steel industry. The bauxite used to produce alumina will soon face the same problem. According to data, according to the current alumina production in my country, the guarantee period of bauxite is less than 10 years, so the development of new iron and aluminum resources is imminent. In 1987, a reserve of about 400 million to...

AI Technical Summary

Problems solved by technology

However, because this type of high-iron bauxite has high active silicon, the direct treatment effect of the Bayer method is not good, and the alkali consumption is large; the use of "iron first, then aluminum" and magnetization roasting consumes high energy, and the economy is not good. In the "aluminum" scheme, there are problems such as difficulty in desiliconization and low extraction rate of alumina in the process of leaching alumina from blast furnace slag