Method for synthesizing ultrafine calcium carbonate by utilizing carbide slag

Abstract

The invention relates to a method for synthesizing ultrafine calcium carbonate by utilizing carbide slag. The method comprises the following steps of: (1) dissolving carbide slag: uniformly mixing carbide slag with water in a ratio of (1:6)-(1:20) to ensure that the carbide slag is fully dissolved into a turbid liquid, wherein the water content of the carbide slag is 20-45%; (2) carrying out impregnation reaction: adding ammonium chloride into the turbid liquid of the carbide slag for uniformly mixing, wherein the mass ratio of carbide slag to ammonium chloride is (1:0.7)-(1:2.5), after the impregnation reaction is finished, filtering and removing the slag to obtain a clear calcium chloride solution; and (3) carrying out carbonization reaction: adding a crystal form control agent into a calcium chloride solution for fully dissolving, introducing CO2 into the solution to carry out carbonization reaction till the pH (potential of Hydrogen) value of the reaction solution is less than or equal to 7 to obtain ultrafine calcium carbonate slurry, wherein the crystal form control agent is one or more than two mixtures of sulfate, chloride, citrate, sodium dodecyl benzene sulfonate, pyrophosphate, oleic acid, ammonium citrate, N-methyl pyrrolidone and maleic acid.

Description

technical field [0001] The invention relates to a method for synthesizing superfine calcium carbonate by utilizing carbide slag. Background technique [0002] Carbide slag is a by-product of the chlor-alkali industry using calcium carbide to produce acetylene gas, and it is an industrial waste. According to survey statistics, my country produces nearly 40 million tons of calcium carbide slag every year, and its utilization rate is less than 30%. Except for a small amount of cement, it is generally disposed of in landfill, which not only occupies a large area of ​​land, but also alkalizes the land, which is harmful to the air. and water sources causing secondary pollution. [0003] With the rapid growth of the global economy and the sharp rise in energy consumption, the "greenhouse gas" CO 2 The rate of emission increases rapidly with the increase of people's utilization of energy, leading to global warming. The combustion of fossil fuels in the cement industry and the calc...

AI Technical Summary

Problems solved by technology

According to survey statistics, my country produces nearly 40 million tons of calcium carbide slag every year, and its utilization rate is less than 30%. Except for a small amount of cement, it is generally disposed of in landfill, which not only occupies a large area of ​​land, but also alkalizes the land, which is harmful to the air. and water sources causing secondary pollution

Although this patent utilizes waste slag and exhaust gas to prepare calcium carbonate, the process is complicated, more equipment is needed, and the content of carbon dioxide is low, and the yield of calcium carbonate is low

Although this patent prepares light and nano-calcium carbonate, nano-calcium carbonate is unevenly dispersed in organic media due to its small particle size, high surface energy, easy aggregation, surface hydrophilic-oleophobic and strong polarity. Causes interface defects between the base material and the filler, so surface activation treatment is required to improve the surface properties of nano-calcium carbonate, adjust hydrophobicity, and improve the wettability and binding force between the base material and the base material

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