Process for roasting waste sand into precoated sand material

Abstract

The invention relates to a process for roasting waste sand into a precoated sand material. The process comprises the steps of shakeout, magnetic separation, crushing, screening, magnetic separation, roasting, dedusting, cooling and storage. When crushed and magnetically separated sand is roasted, the sand is required to be fed into a preheater for preheating, and then is fed into a roasting furnace for roasting. A passage for bearing the sand is stepped when the sand is in the preheater, the sand in the stepped passage is in a flocculated flow state, and when the sand is roasted, natural gas is jetted from three direction-adjustable jet tips in the roasting furnace to process the sand. Before being roasted, the sand is required to be preheated, so that the high-temperature heat exchange time of the sand in the roasting furnace is short, and the roasting efficiency and the roasting quality are improved. The sand is roasted at high temperature by the natural gas, so that the generation of an inert gas during the roasting is avoided. In addition, the three adjustable natural gas jet tips are adopted, so that the sand can be uniformly heated when roasted.

Description

technical field [0001] The invention relates to a process for roasting waste sand into materials for coated sand. Background technique [0002] Manufacturing industry is the pillar industry of our country, and casting is the basic industry of equipment manufacturing industry, but casting is also one of the industries with the largest pollutant discharge. At present, the energy consumption and sewage discharge of castings produced in my country are much higher than those of industrialized countries. For every ton of qualified castings produced in my country, about 50kg of dust and 1000-2000m of exhaust gas will be emitted. 3 , waste residue 300kg, waste sand 1.3~1.5t. Among them, the waste sand has the largest amount, which cannot but be said to be a huge waste. At the same time, the old sand contains a large amount of pollutants, including benzene, phenol, furan, α-benzopyrene, NaOH, KOH, etc. With erosion, these harmful substances flow into the surface, destroy the soil ...

AI Technical Summary

Problems solved by technology

[0004] 1. In the prior art, the magnetically separated sand is directly sent from the storage room to the roasting furnace for roasting. The lack of intermediate preheating process makes the roasting time of the sand in the roasting furnace too long, which affects the quality of roasting;

[0005] 2. Inert gas will be generated during roasting with diesel or kerosene, and it will take time and effort to discharge a large amount of inert gas generated by combustion;

[0006] 3. When roasting with diesel or kerosene, the combustion is mainly concentrated at one point, the combustion is uneven, and the damage to the sand is greater