Corn processing is mainly divided into two types: dry processing and wet processing.
1. Dry processing of corn.
The process of dry processing includes the steps of removing impurities, adjusting moisture, peeling, breaking grits and removing embryos, extracting grits and extracting embryos, and grinding flour to obtain corn grits, corn flour and corn germs. Dry processing workers are divided into three types: whole corn milling method, embryo milling method for flour and embryo, and co-product processing method, which includes corn flour, corn grits and corn germ. 
2. Wet processing of corn.
The process of wet processing includes cleaning, soaking, grinding, separation, refining, dehydration and drying, so that the cellulose, oil, protein and other non-starch substances in the corn kernel are separated to obtain white powdery starch. There are six processes in the wet process, and the resulting products include starch, protein, gluten meal, corn syrup, corn germ oil, cake meal and skin residue, which can be further processed.
The cleaning process is essentially the same as rice processing, but hydrocyclone stone removers and weir tanks can be used to further remove heavy stones and metals. There are two soaking methods, single tank cycle and countercurrent cycle, the purpose of which is to soften the corn kernel and destroy the protein web, removing most of the soluble material for crushing and separation. Crushing and embryo separation generally adopts the process of two crushing and two separation, using a cam mill for crushing, separating the embryo with an embryo cyclone or flotation tank, and then washing through six curved sieves to obtain a net wet embryo. The separation and washing of grinding and fiber is to form a suspension of corn paste with impact mill or grinding wheel grinding, which contains fine residue and coarse residue, and then use a vibrating flat sieve, centrifugal sieve or koji sieve to separate the free starch, gluten fine particles and cellulose and add water to wash it fully at the same time to improve the starch yield. The refining of starch milk is carried out in three ways: launder, centrifugal unit and centrifuge plus cyclone set in corn starch plants in China. The dehydration and drying of starch usually uses a three-legged centrifuge, an automatic scraper discharge centrifuge and a vacuum suction filter to separate the free water in the starch milk through the filter cloth, and the water content of the wet starch obtained is about 40%. Starch drying mostly adopts airflow (also known as flash evaporation) drying, which is a heat exchange in the process of mixing wet starch with a purified high-humidity air flow in a closed pipeline, and the starch can be dried to a water content of 14% in an instant.
3. Corn oil processing process.
The processing and extraction of high-oil corn mainly includes two processes: the separation of embryos and the extraction of embryos. There are two methods of embryo separation: dry peeling and extraction of embryo powder and wet grinding of embryo extraction and powdering. The process of extracting and refining corn oil from the embryo includes the use of pressing method to produce oil, especially the key treatment links before the corn germ is pressed, and the oil channel dredging and crude oil ** in the pressing process, which can effectively improve the ratio of grain and oil. The crude oil produced contains a certain amount of saturated fatty acids, lipids, waxes and cholesterol, as well as non-glycerolipid impurities such as free fatty acids, phospholipids, pigments and a small amount of protein colloidal substances. In addition, it also contains a certain amount of pigment. Therefore, in order to obtain refined corn oil, it must also be treated by dewaxing, deacidification, decolorization and deodorization.
Fourth, corn grits processing process.
The corn grits extraction and embryo extraction of corn grits processing machinery are carried out at the same time, that is, the extraction of grits and the selection of embryos. Generally, the process flow of grits extraction of corn grits processing machinery is mainly for the extraction of grits and embryos of suction specific gravity extraction machine and the extraction of grits and embryos of gravity extraction machine.