The main raw materials used in the cement manufacturing process are limestone, sand, shale, clay, and iron ore. The main material, limestone, is usually mined on site while the other minor materials may be mined either on site or in nearby quarries. Another source of raw materials is industrial by-products. The use of by-product materials to replace natural raw materials is a key element in achieving sustainable development. Cement is widely used in road construction industry, building industry, water conservancy project, and defense industry and so on. Cement industry is a large industrial department in many countries.

Widespread soil acidity is a common soil-related constraint to crop production in many parts of the world including sub-Saharan Africa. High leaching rates, unfavourable parent materials and, in some rare cases, the continuous application of acidifying chemical fertilizers such as ammonium-sulphates are largely responsible for high soil acidity. However, the main constraint for crop production in highly acidic soils is not so much the high amount of H+ but the increased concentration of highly toxic A13+ at low pH, and low exchangeable Ca2+ levels (Sale and Mokwunye 1993).

Mining of limestone requires the use of drilling and blasting techniques. The blasting techniques use the latest technology to insure vibration, dust, and noise emissions are kept at a minimum. We produce whole set of cement making machines: jaw crusher,cement mill,impact cruhser, vibrating screen. Cement production plant contains three parts:

First: coal crusher and coal mill plant;

Second: limestone (clay, alumina) crusher, and milling machine;

Third: gypsum crusher and gypsum mill.

Traditionally, liming materials are evaluated according to their neutralizing value (measured by titration) and fineness (measured as particle size distribution), and in a combined form, the ‘agricultural index.’ Typical ground limestone has a neutralizing value of 100%, dolomite 106% and agricultural hydrated lime, after energy intensive calcination, 136%. Other ways of assessing the expected performance of liming materials is by surface area, chemical composition and solubility. While the fineness is expressed as particle size distribution of ground and sized material, the surface area is expressed as the total surface area of the liming material. The surface area does not necessarily correlate with the particle size analysis as internal pores, cracks and irregular surfaces largely increase the surface area. Only in very finely ground materials, surface area and particle size show strong correlation (Conyers et al. 1996). Liming materials from coral limestone and ‘earthy limestones’ often contain aragonite as form of CaCO3, which is slightly more soluble than calcite. Dolomite is less soluble than calcite.

Crushing and milling machine used in cement plant

Primary crusher: PE jaw crusher, used to crush large raw ores into small rocks, such like coal, limestone, clay, gypsum;

Secondary crusher: PE jaw crusher, impact crusher, PFW impact crusher, used to crush the large ores further more after the primary crusher;

Tertiary crusher: cone crusher, used to crush the large particles into smaller ones less than 3mm;

Ball mill: widely used to grind coal, limestone, gypsum and clay into fine powder, features with high grinding capacity, low consumption etc.

Vertical mill: an ideal equipment to grind coal into powder.

Each cement product is stored in an individual bulk silo until needed by the customer. Bulk cement can be distributed in bulk by truck, rail, or water depending on the customers needs. Cement can also be packaged with or without color addition and distributed by truck or rail.

jaw crusher: http://www.hxjq-crusher.com/1.html
impact crusher: http://www.hxjq-crusher.com/2.html
cone crusher: http://www.hxjq-crusher.com/8.html
Ball mill: http://www.hxjq-crusher.com/20.html


raymond mill: http://www.hxjq-crusher.com/11.html
combination crusher: http://www.hxjq-crusher.com/4.html