Method for producing white carbon black by using high silicon fly ash

Abstract

The invention relates to the fields of metallurgy, chemical industry and aluminum silicate thermal insulation materials, in particular to a method for preparing white carbon black by using high-silicon fly ash. The method comprises the following steps: mixing high-silicon fly ash with lye and filtering to obtain filtrate and filter residue; the filtrate is mold-lifted, filtered, carbonated, decomposed, filtered and dried to obtain a qualified white carbon black product. The invention has simple process and convenient operation, prepares white carbon black and thermal insulation material from fly ash with low aluminum and high silicon content, which is difficult to extract alumina in the prior art, improves resource utilization, improves recycling of lye, and is not only environmentally friendly but also Improved enterprise efficiency.

Description

technical field [0001] The invention relates to the fields of metallurgy, chemical industry and aluminum silicate thermal insulation materials, in particular to a method for preparing white carbon black by using high-silicon fly ash. Background technique [0002] The average content of alumina in fly ash in most areas of my country is about 35%, and the ratio of aluminum to silicon is usually less than 1, which is not suitable for extracting alumina. While SiO in fly ash 2 The content is often as high as more than 50%. According to relevant literature research, it is found that SiO 2 There are many forms in fly ash, mainly including mullite in crystal form, quartz sand and glass body in amorphous form. The degree of difficulty of the reaction of silica with different structures and forms with acid and alkali is quite different. Through the experimental research on fly ash of power plants, it is found that when the temperature is lower than 100°C, SiO in fly ash of power p...

AI Technical Summary

Problems solved by technology

[0004] The existing technology for producing white carbon black is to use quartz sand to add soda ash or caustic soda to produce water glass, and then react water glass with dilute sulfuric acid (dilute hydrochloric acid) to produce white carbon black. The lye cannot be recycled, and energy consumption and alkali consumption are very high

Due to the use of strong acid, corrosion resistance has become the main consideration for equipment selection, and equipment, instruments, and process pipe networks have a large investment and high cost.

Adopting this process will lead to low economic benefits, pollute the environment, and is not conducive to energy saving and emission reduction

Among the existing Chinese technical patents, the invention patent with the application number 200610012780.7 "Method for producing alumina from fly ash and co-producing white carbon black" discloses a technical solution using activated fly ash and ammonium sulfate to react , and then use the separated waste residue to react with sodium hydroxide solution to produce water glass, and then return to the traditional process technology for producing white carbon black. The disadvantage is that the process flow is complicated, the production process is difficult to control, and acid corrosion is difficult to avoid. Serious environmental pollution, high investment in equipment, unstable products, and low economic benefits, so it is difficult to apply to production

The main defects of the technical solution disclosed in the invention patent with the application number 200810112619.6 "A method and system for producing white carbon black by using high-alumina fly ash" are: the pre-desiliconization temperature and pressure in the technical solution are high, and the carbonization process exists Serious defects, process indicators are difficult to control, resulting in unstable product quality, waste residue treatment is to use it to produce alumina first, and then use red mud to produce cement, the materials cannot be balanced, and secondary pollution is bound to occur, and the investment is high, the pollution is serious, and the economic benefit is low. , not conducive to energy saving and emission reduction