WorkVenture gives you an inside look at what it's like to work at Firstsiam Mining Ltd., Part., office & team photos, reviews and more. This is the Firstsiam Mining Ltd., Part. Company Page. All content is posted anonymously by employees currently or previously working at Firstsiam Mining Ltd., Part..Apply to Siam ChemicalsApply to Learn CorporationApply to SagitateApply to Thai O.P.P.