The history of human civilization is thousands of years, and the development history of limestone is more than a thousand years. During the Ming Dynasty in my country, there were records of using limestone to burn lime. With the development of productive forces and the advancement of science and technology, limestone and its products have become the most widely used and the largest amount of mineral raw materials and supplies in various sectors of the national economy, and are indispensable to people’s daily life. This is also called the king of non-metallic minerals. s reason.
(1) Building cornerstone – limestone for cement
Limestone is the main material for the production of cement. Cement is a hydraulic cementitious material made of limestone mixed with other ingredients. It can harden and increase strength when mixed with water. It forms reinforced concrete with sand, stone and steel, and is the most widely used material in the construction industry at present.
Why is cement also called cement? In the old days of China, the industry was backward, and many items were imported products, so it was customary to add the word “foreign” in front of these items. “Cement” is because there is no such thing in China at that time, and its color is like “gray”, so it has the vivid name of “cement”.
(2) Metallurgical helper – limestone for flux
Limestone occupies a primary position in non-metallic raw materials for flux. In the process of metal smelting, limestone will form slag with impurities in the ore, so that the beneficial components in the ore will be smelted into metal. The limestone with high magnesium oxide content can make the slag turn into a liquid state and reduce its melting temperature, making it easy to remove, and is the best flux.
Is ferrous metal really black? What are non-ferrous metals? Ferrous metals are metals and alloys with iron as the basic component. They are not black as people imagine: pure iron is silver-white, chrome is gray-white, and manganese-silver is white. In addition to iron, manganese, chromium, vanadium, titanium, other metals are called non-ferrous metals.
(3) Chemical experts – limestone for chemical industry
Limestone is widely used in the chemical industry, such as the manufacture of calcium carbide, soda, caustic, soda ash, bleaching powder, fertilizers, etc. The main purpose of chemical limestone is to manufacture calcium carbide (calcium carbide is an important basic chemical raw material, mainly used to generate acetylene gas). limit.