Method for preparing high-titanium slag by directly reducing titanium concentrate in gas-based shaft furnace

Abstract

The invention relates to the technical field of direct reduction in the metallurgical technology, in particular to a method for preparing high-titanium slag by directly reducing titanium concentrate in a gas-based shaft furnace. According to the method, titanium concentrate oxidized pellets are used as a raw material, put into the gas-based shaft furnace, directly reduced with reducing gas, then delivered to an intermediate frequency induction furnace, and melted to obtain pig iron and high-titanium slag, wherein the recovery rate of iron in the pig iron is greater than 97%, and the recovery rate of TiO2 in the high-titanium slag is greater than 95%. The method is short and compact in process, high in production efficiency and low in comprehensive energy consumption, and is a new method for efficient, clean and comprehensive utilization of titanium concentrate.

Description

technical field [0001] The invention relates to the field of direct reduction of metallurgical technology, in particular to a method for preparing high-titanium slag through direct reduction of titanium concentrate in a gas-based shaft furnace. Background technique [0002] Titanium has important utilization value and broad application prospects in aerospace, biomedicine, vehicle engineering and other fields. The titanium ore reserves in the Panzhihua area of ​​my country are the largest, accounting for 48% of the total domestic reserves, but most of them are rock ores with dense mineral structures and high levels of calcium and magnesium in solid solution, so the selected titanium concentrates are low in grade and non-ferrous. High content of titanium impurities. Calcium in titanium concentrate mainly exists in two forms of plagioclase and titanopyroxene, and magnesium mainly exists in the form of plagioclase and (Mg, Fe)TiO 3 The form of isomorphism exists, so the phase c...

AI Technical Summary

Problems solved by technology

(1) Coal-based reduction-electric furnace smelting method: the process flow is short, the factory occupies a small area, and the by-product pig iron can be smelted directly, but this method has high energy consumption and large carbon emissions, and the titanium slag is affected by the ash and impurities of the solid reducing agent. Low grade and poor activity; (2) choose chlorination method: simple process, low power consumption, large production capacity, easy to realize continuous production, complete separation of slag and iron, but difficult to solve when dealing with ilmenite with high calcium and magnesium content CaCl 2 , MgCl 2 The problem of accumulating aggregates at the bottom of the furnace, the resulting FeCl 3 Easy to deteriorate boiling, Cl 2 (3) Reductive corrosion method: simple process, low cost, and little pollution, but this method is only suitable for processing high-grade seashore ore, and most titanium concentrates in my country are not suitable for This process; (4) acid leaching method: can effectively remove impurities such as iron, magnesium, aluminum, manganese, and obtain high-grade (90-96%) artificial rutile, but the secondary process is long, and a large amount of liquid waste needs to be discharged

[0004] Patent CN 102399994B discloses a method for smelting titanium slag. In this method, the mixture of titanium concentrate, binder and carbonaceous reducing agent is made into pellets or briquettes, and ring furnace or rotary hearth furnace is used to pre-reduce the balls. Metallized pellets or metallized briquettes are produced from agglomerates or briquettes, and then melted in an electric furnace to obtain semi-steel and titanium slag. This method belongs to a typical coal-based reduction-electric furnace smelting process. The carbonaceous reducing agent Ash and impurities are unfavorable to the grade and activity of titanium slag; secondly, a large amount of carbonaceous reducing agent is used to melt the slag TiO 2 High content, easy to form titanium carbide with high melting point, affect the viscosity of slag, and is not conducive to the efficient separation of iron and titanium slag; at the same time, the rotary hearth furnace or ring furnace mainly uses radiation heat transfer, and the thermal efficiency is not high. Using it for agglomerate reduction, energy consumption Large, it is difficult to increase the metallization rate of the product, and increase the melting load

Patent CN106591600A discloses a method for preparing high-titanium slag by low-temperature gas-based reduction of ferrotitanium-containing mineral powder. This method uses powdered materials for gas-based reduction, its production capacity and processing capacity are limited, and powder materials are used for production When the particle size of the powder is relatively fine, it is difficult to control the production directly into the furnace, which is not conducive to maintaining the stability of the reduction furnace. In addition, this method adds a molten catalyst Na during the melting process. 2 CO 3 , where Na + It has a great impact on the lining of the electric furnace and will aggravate the erosion of the lining