Cement clinker and preparation method

Abstract

The invention discloses cement clinker. The raw materials are prepared by the following materials by weight ratio: 37-77 percent of waste crushed stone concrete, 10-20 percent of iron ore, 10-20 percent of chromium salt slag, 1-10 percent of clay, 5-15 percent of coal and 1-4 percent of sulfuric-acid residue. The method for preparing the cement clinker comprises the following steps: 1, crushing and pre-homogenization; 2, raw material homogenization; 3, preheating and decomposition: a preheater is used for completing preheating and partial decomposition of the raw materials; 4, cement clinker sintering: after completing preheating and predecomposition in a cyclone preheater, the raw materials enter a rotary kiln for sintering of the clinker in the next procedure; and 5, cement grinding, so as to obtain the cement clinker. According to the invention, the use amount of high-quality limestone can be reduced, Cao and Mgo contained in chromium salt slag do not need thermal decomposition, and each ton of clinker can save raw materials by 10-20 percent; and due to fluxing and mineralization action of microelements, the viscosity of a liquid phase is reduced, and the mechanical strength of the cement clinker is greatly enhanced.

Description

technical field [0001] The invention belongs to the field of building materials, and in particular relates to a cement clinker and a preparation method thereof. Background technique [0002] Chromium salt is a widely used industrial raw material, but producing one ton of chromium salt will discharge 4-5 tons of chromium salt slag, so some domestic chromium salt factories discharge chromium salt slag piled up like mountains, occupying a large area of ​​land. A more serious problem is that the chromium salt slag contains residual water-soluble toxic substances-hexavalent chromium ions (Cr+6). According to laboratory analysis, 1g of chromium salt slag contains as much as 5mg of Cr+8 water-soluble oxides. This kind of chromium salt slag with such a high content of toxic Cr+6 will cause serious pollution to the ecological environment if it accumulates for a long time. GB5085-- 85 The discharge of water-soluble oxides containing Cr+8 is strictly controlled at 1.5 mg per liter of ...

AI Technical Summary

Problems solved by technology

[0003] With the development of the country's economy and construction industry, a huge amount of waste concrete is produced every year due to the demolition of old buildings, and the generated constr