Technical Requirements For Granite

The industrial technical requirements for granite vary depending on its use.
1. Main requirements for natural granite raw materials:
The main requirements for natural granite raw materials in the building materials industry standard (JC-204-92) are as follows:
The raw materials must have the shape of a right angled parallelepiped. The large surface of the waste material should be parallel to the joint surface or pattern direction of the rock.
The specifications and dimensions of the raw materials require a length greater than or equal to 140cm, a width greater than or equal to 60cm, and a height greater than or equal to 60cm.
The appearance quality requires that the color tone, pattern, and particle structure of the same batch of raw materials should be basically consistent. The quality requirements for missing corners, edges, cracks, color lines, and color spots of raw materials shall comply with the provisions of Table 4.24.6.
Physical performance requirements: density not less than 2.50g/cm3; Water absorption rate not exceeding 1.0%; Dry compression strength not less than 60.0MPa; The bending strength shall not be less than 8.0MPa.
2. Quality requirements for acid and alkali resistant granite:
(1) The main chemical composition requirements for acid resistant granite are SiO2>70%~75%, and the higher the content, the better the acid resistance; Al2O3>13%~15%;Fe2O3<0.5%;CaO<0.8%;MgO<0.4%; The acid resistance is greater than 97.5%. Hard. The thermal resistance (compressive strength after 10-40 thermal changes) is greater than 16.2MPa, the melting point is 1610 ℃, the expansion coefficient is less than 8 × 10-3, and the water absorption rate is less than 1.5%.
(2) The quality requirements for alkali resistant granite require high CaO and MgO content, with better alkali resistance. Some acid resistant stones have high SiO2 content but low porosity, and can also be used as alkali resistant stones.