Method for extracting TiO 2 and SiO 2 in blast furnace slag

Abstract

The invention relates to a method for extracting TiO 2 and SiO 2 in blast furnace slag, comprising the steps of dissolving the blast furnace slag with hydrochloric acid, treating the filtrate with alkali, separating TiO 2 and the SiO 2, and the like. The method can completely recover titanium component and silicon component in the blast furnace slag, and has low cost, little pollution and high efficiency.

Description

technical field [0001] The invention relates to a recovery TiO 2 and SiO 2 method, especially involving a method for extracting TiO from titanium-containing blast furnace slag 2 and SiO 2 Methods. Background technique [0002] Titanium dioxide, commonly known as titanium dioxide or titanium dioxide. Due to its excellent physical and chemical properties (high melting and boiling point, strong stability, strong adhesion, extremely white color, non-toxic, etc.), titanium dioxide is an important chemical raw material and daily and industrial coatings, and is often used It is used to make refractory glass, glaze, enamel, clay, high temperature resistant experimental utensils, etc. In 2006, the global output of titanium dioxide was 5 million tons, and it was increasing at an annual rate of 3-5%. my country is a big country in the production and consumption of titanium dioxide. In 2005, the output of titanium dioxide reached about 700,000 tons, and it is expected to reach mor...

AI Technical Summary

Problems solved by technology

There are two problems in this process: 1) a large amount of waste acid is produced, which pollutes the environment relatively; 2) the by-product of the sulfuric acid process is sulfate, and no effective application path for these sulfates has been found at present

However, there are two problems: 1) the loss of carbon powder in the high-temperature carbonization stage is large, the carbonization time is long, the utilization coefficient of the carbonization furnace is small, and the energy consumption is high; Furnace development, etc. still need to be solved through industrial tests

This process successfully produces high-grade titanium dioxide through blast furnace slag, but there are still some problems: 1) The whole process undergoes melting-crystallization-acid leaching and other procedures, and the process flow is long; 2) The crystal form is affected by temperature during the blast furnace slag melting process Large changes and high energy consumption; 3) Perovskite crystallization is greatly affected by the cooling rate, and the whole process is not easy to accurately control; 4) Sulfuric acid leaching of artificially synthesized perovskite has a large environmental pollution

High-concentration hydrochloric acid needs to be produced by a special method, and the price increases significantly; (2) the amount of acid used for decomposition is 6-8 times the weight of blast furnace slag, and 6-8 tons of 32-40% hydrochloric acid is required to treat 1 ton of slag, which greatly increases the cost (3) The reaction needs to be carried out at 80-110°C for 6-20 hours, which not only consumes a lot of energy, but also is more corrosive under this condition, and requires high equipment and environmental measures; (4) The amount of residue after acidolysis is large, Its dry weight is estimated to be more than 25% of the original blast furnace slag weight. This slag has little use and produces new three wastes; (5) the mixed titanium dioxide composed of titanium oxide and silicon oxide produced by this method has considerable The acidolysis insoluble matter, its product purity is very poor, use is little, and output value is also low

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