Mineralogical characteristics of graphite ore from Bao Ha deposit, Lao Cai Province and proposing a wise use

Abstract

Graphite, especially, high quality graphite can be used in many industrial applications including metallurgy, batteries, fuel cells, and refractories. In 2011, Vietnam Ministry of Natural Resources and Environment issued a mineral exploration license to explore Bao Ha graphite deposit, Bao Yen district, Lao Cai Province. The studied samples were taken from 3 drill holes of the Bao Ha largest ore body. Different methods including light microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and carbon and sulfur analyzer were performed to identify its lithological and mineralogical characteristics as well as graphite quality, then propose a wise use of the resource. The Bao Ha graphite is characterized as disseminated flake graphite in massive form, which developed in the sillimanite schist and quartz-biotite schist of the Ngoi Chi formation. Graphite flakes occur as distorted clusters of flaky plates/flakes within 50÷500 mm, which is the medium size in comparison with the general grain size of graphite flake. Graphite particle makes up 33÷43% by volume and graphitic content (Cg) makes up 10.0÷11.7 wt.%. Impurities include mainly quartz, biotite, and feldspar (combining of K-feldspar and anorthite, the primary ore) or kaolinite (the weathered ore). This graphite ore should be refined to reach an ore concentration of at least 90% Cg for domestic industries of metallurgy, batteries, thermal materials, and refractories as well as for exports.ReferencesAsbury Carbons, 2015. Natural graphite - Introduction to natural graphite. http://asbury.com/technical-presentations-papers/materials-in-depth/natural-graphite/(Accessed on April 26, 2015). Bergmann J., Friedel P., Kleeberg R., 1998. BGMN - a new fundamental parameters based Rietveld program for laboratory X-ray sources, its use in quantitative analysis and structure investigations. CPD Newsletter 20, 5-8. Bien Xuan Thanh (Editor), 2014. Exploration of graphite deposit in Bao Ha area, Bao Ha community, Bao Yen district, Lao Cai province. Report. Song Da Lao Cai Mining Joint Stock Company. Cameron E., 1960. Graphite: Industrial Minerals and Rocks. Seeley W. Mudd Series, AIME (Chapter 20). European Commission, 2010. Report lists 14 critical mineral raw materials. http://europa.eu/rapid/press-release_MEMO-10-263_en.htm?locale=en. (Accessed on April 26, 2015). Garnier V., Giuliani G., Ohnenstetter D., Fallick A.E., Dubessy J., Banks D., Vinh H.Q., Lhomme T., Maluski H., Pêcher A., Bakhsh K.A., Lon…