Dolomite in Nepal

 

Exploration for dolomite was not much emphasized in the past due to either absence of dolomite base industries or its small likely requirement in the industries. ln many cases the carbonate rocks when searched as the cement grade limestone as raw material for cement industry, the associating dolomite were discarded as undesirable ingredient. Hence their documentation has not been properly made and real situation of the dolomite still remain obscure except in one case like the identification of 4.2 million tons of good quality dolomite in the Udaypur Limestone deposit.(Mineral Resources of Nepal,2023)

For many limestone resources examined in the past, assessment in terms of identifying industrial dolomite is either lacking or with sketchy data. Recently the Department of Mines and Geology for the industrial dolomite in Dhading, Arghakhachi and Baitadi regions to fulfill the emerging demands in the paint, soap and detergent industries. To date good quality dolomites are observed in association with the limestone deposits at Baitadi, Bajhang, Bajura, Arghakhachi, Surkhet, Salyan, Dang, Rolpa, Palpa and Kavre districts that need evaluation in terms of availability of quantity. Preliminary geological investigation result revealed that there exists over 2 billion tons of dolomite in the country. One mine of industrial dolomite is in operation in Dhading and another in Tanahu. (DMG)

Dolomite occur mainly in Mahabharat range in Dhankuta, Khotang, Udayapur, Sindhuli, Dolakha, Kavre, Kathmandu, Makwanpur, Dhadhing, Syangja, Palpa, Baglung, Gulmi, Arghakhanchi, Dang, Pyuthan, Sallyan, Rolpa, Rukum, Jajarkot, Surkhet, Dailekh, Jumla, Achham, Doti, Bajhang, Bajura, Baitadi and Darchula districts in the Lesser Himalaya and in some parts of Higher Himalaya and Tibetan Tethys (Inner Himalaya) region (Kaphle, 2005, 2020). 

The quality of dolomite depends on its chemical composition like MgO%, CaO%, SiO2%, Al2O3%, Fe20%, LOI%. Depending on these oxides it can be used in different industries. Dolomite is a potential source of metallic magnesium. It is used to manufacture soral cement and also in refractories, high magnesium lime, flux for iron and steel industries, ferroalloy industries, fertilizer industries and acid water treatment plants. Dolomite can be directly used in agricultural field to neutralize acidity and also to make up the loss of magnesia in soil. MgCO3 is used on a small scale as filler in the paper, paint, rubber, varnish and pharmaceutical industries. In huge amount it is used as building/ construction stone, aggregate for concrete, road fillings and asphalting materials.

Uses:

·       Dolomite has applications as a building and decoration stone in construction, as a flux in steel industry and as filler in glass industry.

·       It is also used in paint, soap, detergent and agriculture purposes. It is used to manufacture refractory bricks, mineral wood, magnesium and also to manufacture soral cement.