Nongle Glauberite Geological Characteristics And Economic Evaluation In West Sichuan Depression

Nongle glauberite deposit is located in Meishan–Puxingchang secondarydepression of West Sichuan depression. It is a Mesozoic continental clastic rock typeglauberite deposits. It is hosted by the upper Cretaceous Guankou group.The deposits are characteristic of multiple-seam.Ore belt is controlled byXiongpo anticline south east wing.Its strike is NE–SW.Dip is SE. Angle of dip is4¹2degrees. Average thickness of ore-bearing zone is220.37m.There are20to30layers of glauberite seam in the ore-bearing belt.There are104.20m thick strata in theore belt of central.Ore-bearing zone is divided into upper ore belt and lower ore belt.Ore structure is automorphic granular texture and hypautomorphic granulartexture.Ore structure has pattern structure, banded structure and disseminatedstructure. Ore minerals include glagerite, mirabilite.Gangue minerals are anhydrite,gypsum, clay, dolomite, calcite, quartz, and so on.Ore chemical composition ofglauberite deposits is mainly Na₂SO₄, CaSO₄, MgSO₄, NaCl, crystal water and waterinsoluble matter, etc., which Na₂SO₄content is generally25%to40%.The late Triassic to the early Cretaceous sedimentary facies evolution program inthis region is paludal faciesâ†'plain riversâ†'pluvial phase, plain rivers and lakeâ†'drylake.The second paragraph of Guankou group formation is the product of dry lake.Lithofacies change has an obvious rule,that is sandy debrisâ†'calcareous clay-contain-ing debrisâ†'sulfatesâ†'clay powder sandy debris. Variation of salt-containing mineralsare carbonatesâ†'sulfates.The economic evaluation of3,4ore seam in lower ore belt as object, on the basisof financial analysis table method combined with dynamic net present value method,economic benefit of sodium sulfate from glauberite mining production is calculated.The results show that calculation to mine design and production capacity of800,000 tons/year （hydro sulphite of soda20tons/year） and production period of30years,the total profit is about200million yuan.Investment profit margin is29.79%.Investment profit margin is much higher than the benchmark rate of return oninvestment. Micro-economic efficiency is good. Mine development prospects isoptimistic.