Overview of Bentonite for Foundry

1、 Overview of Bentonite in the United States
Bentonite in the western United States is mainly produced in Wyoming State, with some mineral deposits in Montana State in the north and South Dakota State in the east. The western bentonite mineralization occurred in the Cretaceous period (67 million to 137 million years ago) before the formation of the North American continent, and was formed by volcanic ash accumulation on the seafloor. The ore veins extend for about 250 km, all of which are sodium based bentonite.
Bentonite in the southern United States is mainly produced in Alabama and Mississippi states, and neighboring states also have mineral deposits, but these two states account for approximately 70% of the reserves. The southern bentonite was formed during the Tertiary Xiaocene (55 million to 65 million years ago), and the bentonite produced is calcium based bentonite, commonly referred to as southern bentonite.
The mineral deposits in Wyoming State mainly include two mining areas.
1. Black Hills mining area
Heishan Mining Area is located in the northeast of Wyoming State, and the bentonite produced is relatively suitable for preparing clay green sand in the casting industry. Bentonite from the same mining area has different physical properties in different ore layers. There are nine main layers of bentonite in the Heishan mining area. When Bentonite Corporation of the United States mines, it selects the applicable layer for mining, and mixes and mixes various layers of bentonite with basically the same physical properties. The final product is divided into four categories:
The type close to the surface layer is Yellow Type;
Intermediate layer;
The lower layer is of the Blue Type, which has the best taste, and is further divided into two categories.
2. BLUE HORN mining area
The mining area is located in the central part of Wyoming State, and in terms of mineral grade, it is generally superior to the low grade ore bed of Black Hills, but slightly inferior to its high grade ore bed.
3. Information about American Colloid Company
ACC is the largest enterprise engaged in the mining, preparation, and supply of bentonite in the United States. It can be said to be a world leader in terms of equipment conditions, product output, and market size. Currently, there are 7 mining and milling plants, 6 mixing plants, and 5 overseas companies (2 in Australia, 1 each in Canada, the UK, and China). Volclay International Ltd is a wholly-owned subsidiary of ACC.
ACC has been mining bentonite in Deadwood, South Dakota, since 1927. By 1935, it had successively built factories in Bell Fourche, Upton, and other places in Wyoming. In 1987, it purchased mining sites and production plants in Wyoming State from AIMCOR and other companies.
ACC also owns mineral sites and production plants in Alabama and Mississippi states in the southern United States, producing calcium based bentonite. Currently, ACC produces about 2 million tons of sodium based bentonite and about 700000 tons of calcium based bentonite annually. About 40% of the bentonite exported by ACC is sold to Japan.
2、 Overview of Bentonite in China
Exploration research shows that China has the largest reserves of bentonite in the world, with a complete range and wide distribution, covering 26 provinces and cities, and ranking among the world’s top producers and exporters. According to incomplete statistics, the annual production of bentonite in China has exceeded 3.5 million tons, and the total reserves account for 60% of the world’s total. Currently, the accumulated proven reserves are over 5.087 billion tons, and the retained reserves are over 7 billion tons.
More than 100 proven bentonite ore producing areas are mainly distributed in Xinjiang, Guangxi, Inner Mongolia and the three northeastern provinces. Among them, the reserves of bentonite ore in Hoboksar Mongol Autonomous County in Xinjiang have exceeded 2.3 billion tons, making it the largest bentonite mining area in China with proven reserves. According to the Xinjiang geology and mineral resources department, there are 7 bentonite deposits in Hoboksar Mongol Autonomous County, including 4 large deposits (Ulan Yingge, Riyulei, south and southwest of the Delun Mountains). The geological reserves of bentonite ore in Wulanyingge mining area are 572.8 million tons, including 229.48 million tons of on-balance sheet C-D grade bentonite ore reserves and 2.48 million tons of off-balance sheet D-grade bentonite ore reserves, accounting for 13.74% of the national equivalent bentonite reserves. The geological reserves of bentonite ore in the Riyueli mining area are 800 million tons, while the geological reserves of bentonite ore in the south of the Delian Mountains and the south of the Delian Mountains are 210 million tons and 0.8 billion tons, respectively. Experts estimate that the prospective reserves of bentonite deposits in the Ulan Inge region are expected to exceed 5 billion tons. The producing areas in Guangxi include Ningming, Tiandong, Chongzuo, Guiping, Hengxian, and other places. The largest reserve is Ningming, with a total of 640 million tons, followed by Tiandong, with a total reserve of over ll billion tons. Ningcheng, Xinghe, Huolin, Guyang and other places in Inner Mongolia are all rich in bentonite minerals, with the largest reserves being Ningcheng, Chifeng, with over 1 billion tons. The rest are distributed in Jiangsu, Sichuan (Nanchong), Hebei, Hubei, Shandong, Anhui, Zhejiang, Jiangxi, Henan, Shaanxi, and Gansu provinces.