1. But Phong cement limestone mine
The geology of But Phong cement limestone mine in Kim Bang district is characterized by layers of limestone of 0.7 to 1.2 m thick containing dolomitic limestone ranges of up to 700m thick. The thickness of industrial limestone is 300m. Its components are CaO: 52.62%, SiO2: 2.55%, etc. The potential reserves of the mine is large, about 130,751 million tons.
2. Hong Son cement limestone mine
Hong Son limestone cement in Kim Bang is a cement limestone mines located on a stretch of Dong Giao limestone floors, of 600 meters long, 400 meters wide, including five layers from the bottom up:
- Black limestone of unknown thickness;
- Dark gray and white gray limestone in 2 blocks, 500 meters thick;
- Limestone with dolomite, 5 feet thick;
- Limestone with large amount of dolomite, 10 meters thick;
- Dolomite limestone.
The composition of limestone here is as follows: 53.96 % CaO, 0.42 % MgO, ... The mine has the potential reserves of about 61.706 million tons.
3. Dong Ao cement limestone mine
Dong Ao cement limestone mine in Thanh Liem district consists of limestone ranges of up to 1,200 m long, 50m - 500m wide. Industrial limestone is distributed in the Northwest of the ranges with the thickness of 600m, width of 300m. In the southeast, industrial limestone is in the form of lenses interlaced in dolomite. The stone is white gray or dark gray. The limestone comprises: 52.96% CaO, 2.39% MgO, 0.41 % SiO2, ... Mine has potential reserves of about 12.433 million tons.
4. Thanh Tan cement limestone mine
Cement limestone mine in Tan Thanh Thanh Liem district is part of limestone bands distributed in two landmark mountain areas and mountain solved. Size distribution in limestone solved approximately 570m, 100 - 370m wide. White limestone gray, solid, sometimes have lenses dolomite. The limestone comprises: 53.30 % CaO, 2.05 % MgO... The mine has the potential reserves of about 5.388 million tons.
5. Kien Khe chemical limestone mine
Kien Khe chemical limestone mine in Thanh Liem district is a limestone mine in the delta area. Its explored area is about 500m long, 100m wide. This is an industrial limestone mine (pure limestone), of gray, blue, or white gray colors, with Calcite content > 95%. The limestone comprises CaO: 54.23 to 54.25 %, MgO: 0.61 to 0.55 %. The potential reserves of the mine are about 2.222 million tons.
6. Thanh Son chemical limestone mine
Chemical limestone quarries in Thanh Son Kim Bang district are located near the western margin mines Son Cement Company, with a total area of 3km2. Mine is a mountain range stretching carbonate rocks of the north - south, at an altitude distribution of 70 - 326m, located in Dong Giao infrastructure. Limestone composition comprises: CaO 54.30 to 55.19 %, MgO: 0.57 to 0.85 %, SiO2: 0.13 to 0.71 %. The potential reserves of the mine is about 163.084 million tones of stones for the chemical industry, 414.428 million tons for the cement industry and about 12.463 million tons of stones for construction.
7. Thanh Nghi chemical limestone mine
Thanh Nghi chemical limestone mine in Thanh Liem district is adjacent to the right bank of Day River, nearly 1.5 km away from National Highway 1A. Limestone exposed at a height of 7.5 – more than 180 m, creating mountain slopes stretching along the meridians. Limestone here belongs to the Dong Giao system, divided into three layers of industrial limestone:
- Chemical limestone (pure limestone): Calcite 90-98 %, dolomite 0-3 %, CaO 55.04 - 55.33%, MgO 0.41 - 0.80 %, SiO2 0.05 – 0.16 %,
- Cement limestone: Calcite 90 - 95%; dolomite 3-5%; other minerals accounting for less than 5%, CaO 53.89 - 54.94%, MgO 1.16 - 1.43 %, SiO2 0,09 - 0.20%, ...
- Limestone for constructions is of a smaller proportion, consisting of dolomite stones, ash gray and dark gray dolomite-lime, small-grained structure; divided into different layers or in form of lenticular.
The mine has the potential reserves of 154.610 million tons (chemical industry); 59.725 million tones (cement industry); 0.337 million tons (stones for construction). This is a large limestone mine.
8. Ha Nam construction limestone mine
Ha Nam (Thanh Nghi) construction limestone mine in Thanh Liem district is a mine in Dong Giao system. Its composition consists of thick layered limestone, strongly cataclastic dolomite, dolomitized limestone. The body of the limestone ore has particles of 0.1 to 0.3 mm. Its composition includes 52.55% CaO, 2.3% MgO, and 1.15% HO. The mine’s potential reserve is approximately 1.004 tons (large mine).
9. But Son dolomite mine
But Son dolomite mine in Kim Bang district is a dolomite mine in Dong Giao limestone formation, forming low and slope hills. Dolomite here is in the form of multi-layer lens. The mine consists of 3 areas: Hanh Lam, But Son and Tan Son. 51% of the reserves are in But Son, 33% in Tan Son and only 16% in Hanh Lam.
There are two types of dolomite:
- Solid dolomite, with fine to medium grains, dark gray;
- Weathered dolomite distributed on the surface.
Dolomite can be used in the glass industry. Its composition includes MgO 19.3% - 22.68%, CaO 28.81% - 33.31%, and HO 0.21 to 1.16%. The mine has the potential reserves of about 36.142 million tons (large mine).
