Sand and Gravel Production Line,Sand and Gravel Quarrying Process

Sand and gravel are widely used as bedding material, in preparation of concrete mixes, and in many other construction applications. An estimated 90 percent of commercial sand and gravel is produced from “loose material.” Only about 10 percent comes from hard rock.

Steps for Produce Sand and gravel

1. In a typical operation, rock less than 12 inches, long dimension, is screened through coarse bar screens (“grizzlies”) and the passing material is crushed in a jaw crusher to inter­ mediate size rock.

2. Coarse-crushed rock passes through a three-level screen, and oversize material is re­ turned to the jaw crusher.

3. The smallest, sand size fraction is stockpiled for use in concrete, while the inter­ mediate size rock fraction is either stockpiled for aggregate (nominally 1 inch and below), or is further crushed in a gyratory cone crusher.

4. Crushed intermediate material is screened, and oversized material is returned to the cone crusher, or further processed in a rolling mill or a vertical impact mill, depending on product specifications.

5. The size fraction that passes the screen drops into a tank (or vat) from which sand size material (3/16 inch to ¼ inch and be­ low) is withdrawn with a sand screw (about half of the installations). As an alternative, the fraction passing through the screen may be classified according to size in a gravity classi­ fier (about half of the installations) to recover the sand fraction.

6. Clays and silts are sent to a settling pond, from which decanted water is returned for use in the process.
Overall, a typical sand and gravel plant might produce 70 to 80 percent of its processed ma­ terial as gravel and 20 to 30 percent as sand. Clays and silts normally comprise less than 10 percent of a viable loose material deposit;the settled clay mass might contain around 5 percent solids and 95 percent moisture.

Product for Sand and Gravel