Calcium carbide slag is the waste residue mainly composed of calcium hydroxide after hydrolysis of calcium carbide to obtain acetylene gas. The preparation of chemical products from carbide slag is for the purpose of resource recycling, and the development of green processes and reduction of technology costs will be the focus of future research. HCMilling(Guilin Hongcheng) is a manufacturer of calcium hydroxide slaking and calcium carbonate grinding mill equipment. The following will introduce you to the process of preparing nano calcium carbonate from carbide slag.

Nano-calcium carbonate is widely used in rubber, plastics, papermaking, ink and other fields, with huge market potential. In industry, the carbonization method is mainly used to produce nano-calcium carbonate, and CaO is obtained by calcining limestone, which is digested and suspended Ca(OH)2 Crush, add crystal form control agent, pass CO2 carbonization, dehydration, and surface treatment to obtain nano-calcium carbonate. During this process, waste gas (CO2), waste water (white water) and waste residue will be generated, which will eventually lead to a decrease in product quality and reduce or realize the three wastes Zero emission and improving the quality of nano-calcium carbonate are the key issues, and carbide slag is completely in line with the environmental protection concept of treating waste with waste.

At present, the preparation of nano-calcium carbonate from calcium carbide slag mainly includes three methods: calcination slaking, hydrochloric acid leaching and ammonium chloride leaching. Li Rui et al. used the process route of calcination and pressure slaking to make calcium carbide slag react with CO2 flue gas in a pressurized carbonization reactor to obtain spherical nano calcium carbonate (60nm). This process not only solves the pollution of CO2 waste gas, but also obtains High value-added products; Liu Fei et al. adopted the hydrochloric acid leaching process, acidified calcium carbide slag with hydrochloric acid with pH=8, and carried out metathesis reaction with sodium carbonate. The results showed that the acidified calcium carbide slag would promote calcium carbonate whiskers The occurrence of agglomeration and coarse forked branches eventually leads to aragonitic calcium carbonate whiskers with uniform distribution and high aspect ratio (30-60). Compared with high-purity raw materials, it is found that the nano-carbonic acid prepared from calcium carbide slag The calcium meets the national standard and alleviates the pollution caused by carbide slag. This process proposes an effective process route for the preparation of nano-calcium carbonate.

Zhu Min and others used ammonium chloride to pretreat calcium carbide slag, and then prepared nano-calcium carbonate by carbonization. The results showed that when the concentration of ammonium chloride solution was 8%, the utilization rate of calcium carbide slag was over 92%. Type nano-calcium carbonate (average particle size is 38nm), the purity and whiteness of the product obtained by this process are up to 99.65% and 98.60% respectively, which solves the problem of low purity and poor whiteness caused by impurities to nano-calcium carbonate, and is a good solution for subsequent industrial applications A good process route is provided.

In summary, a large amount of CO2 is used in the preparation of calcium carbonate slag, and high value-added utilization of calcium carbide slag can be realized at the same time. However, it is easy to generate wastewater when the surface is modified by chemical additives. If it is not treated, it will cause secondary pollution. Follow-up needs Further comprehensive consideration is given to the by-products of the reaction to realize the recycling of carbide slag.

If you are interested in Calcium Hydroxide slaking Calcium carbonate grinding mill, please contact mkt@hcmilling.com or call at +86-773-3568321, HCM will tailor for you the most suitable grinding mill program based on your needs, more details please check www.hcmilling.com. Our selection engineer will plan scientific equipment configuration for you and quote for you.