Today lime stone is the main raw material for many industries. The mining process is conducted through many stages before the finished stone is given to many different industries. Mining process includes some steps as below:
The first step: Stripping the soil and processing headstone
Due to the fact that the outer layer of the mine includes soil, stone, flora, we have to drill and blast with small hole sizes, the aim is to give up and remove the entire outer layer of the mines including land, low-quality stone and flora.
It is very difficult and dangerous in the mining process of headstone (because the stone can fall freely when blasting) therefore we have to process it thoroughly to ensure the security during the mining process.
The second step: Drilling and blasting
After stripping the soil and procesing headstone, we will drill by dedicated machine and blast lime stone.
After blasting the lime stone, we will go on classifying, for the big size of lime stone we blast to make it to smaller size. After finishing of lime stone classification, we transport it from moutain to our plant for crushing and sorting. The distance depends on the calculation of the mine owners, always as near as possible to save costs and ensure absolute safety when drilling and blasting.
The third step: Crushing and classification
Lime stone which is transported from moutain will be put in the bunker, then slides directly down to stone hammer. After that the lime stone goes on the conveyer and vibrating screen (capacity 200m3/h). From vibrating screen, the lime stone is classified into requried sizes under each separate gutters. There are some kinds of lime stone products as follows: Lime stone size <1cm, size 1x2cm, and size 2x4cm, size 4x8cm. Lime stone size < 1cm is used in the asphaltic concrete, adobe bricks industries, etc.
The fourth step: Transportation
After sorting the size of lime stone we deliver it to yard at our plant.
The fifth step: Distribution
Lime stone size 1x2cm is distributed in local construction industry. Lime stone size 2x4cm is exported to cement factories world-wide. Lime stone size 4x8cm (which covers about 60% of all kind of lime stone after sorting) is used for manufacturing industrial lime at our plant.
Mining process chart:
Grinding process chart:
Stone (under 700mm size) is transported by 15 ton dump truck from mine to grinding plant where it is poured directly into vibratory bowl to remove subbase impurities before entering jaw crusher (capacity 300tons/hour). Then crushed stone is delivered to bowl feeder and transferred to classifying screen by conveyor belt.
Stone (over 200mm size) returns to impact crusher and bowl.
Stone (under 10mm size) is transferred to cone crusher where it is grinded then delivered to 0.5mm screen. Stone under screen is put into store while stone above screen returns cone crusher.
Photos of Lime Stone mining :