Method for producing reduced iron and Portland cement clinker by using low-grade refractory iron-containing minerals

Abstract

The invention discloses a method for producing reduced iron and Portland cement clinker by using low-grade refractory iron-containing minerals. The method comprises the following steps of: adding brown coal powder, NHC, calcium carbonate and an adhesive into the refractory iron-containing minerals, pelletizing, drying, dehydrating, performing deep reduction, cooling the clinker balls, performing ball milling, feeding the produced ore pulp into a magnetic separation system, and sorting by a magnetic separator, thereby obtaining the reduced iron powder with the total iron content of more than 92% and the metallization ratio of more than 93%, wherein the iron powder is subjected to briquetting molding and is used for electric steelmaking, harmful substances are subjected to a high-temperaturechemical reaction to form silicate to enter tailings, the tailings are used as Portland cement auxiliary materials, the reduced tail gas is used as heat energy of the drying system, finally the tailgas is subjected to segmented cooling, dust collection, tail gas purification and compression separation treatment, the reducing gas is returned and reutilized, the purified and standard gas is introduced into lime water to form calcium salts such as calcium carbonate, calcium sulfide and the like, and the calcium salts are fished out and added into the iron-removal tailings to serve as the Portland cement clinker. The method is energy-saving, environment-friendly, easy to operate, low in cost and high in treatment efficiency.

Description

Technical field[0001]The invention belongs to the field of comprehensive utilization of low-grade iron-containing minerals, and specifically relates to a method for producing reduced iron and Portland cement clinker by using low-grade hard-to-select iron-containing minerals.Background technique[0002]Iron-containing minerals refer to materials produced during the smelting process that contain more than 15% iron, 1.0-3.0% sulfur, and less than 0.1% heavy metals (such as arsenic and antimony). Iron slag is widely derived from non-ferrous metal smelting process. For example, the hydrometallurgical process of gold, the pyrometallurgical process of copper, the process of producing sulfuric acid by fire method in sulfuric acid plant, and the process of extracting sulfur by fire method all produce large amounts of iron-containing slag. The total iron content of sulphur slag accounts for 18%-27% of the slag content. The sulphuric acid slag has the highest total iron content. The total iron c...

AI Technical Summary

Problems solved by technology

The total iron content of iron slag produced in the copper slag pyrometallurgical process generally accounts for about 40% of the slag. my country is rich in lean ore resources, but most iron ores cannot be enriched and belong to refractory ores, such as limonite and hematite , the total iron content generally does not exceed 50%, which cannot be directly used as iron-making raw materials, and it is difficult to enrich by ordinary beneficiation methods, and the iron and steel industry has not been able to use it for a long time

[0003] my country's gold smelters, sulfuric acid plants, sulfur plants and copper smelters will produce 3 billion tons per year. The industry predicts that in the next 2 to 3 years, industrial solid waste tailings may exceed 4 billion tons. Iron smelting slag exceeds 1 billion tons. If it is piled outdoors for a long time without recycling, it will not only cause waste of resources, but also cause environmental pollution.