Extracting mineral fibres from rocks - by adding magnetic powder, magnetically grading to obtain fibre concentrate and opening and purifying fibre content

摘要

Mineral fibres are extracted from rocks by adding ferromagnetic powder to triturated rock and subjecting the resultant mixture to a magnetic grading to separate a magnetic concentrate consisting of grains rich in fibre from a waste product practically free of fibre. The fibre contained in the concentrate is then opened and purified. Used for removal of commercial asbestos from certain rocks. The quantity of rock needs to be subjected to final stages of fibre extraction is reduced and produces a residue of commercial value which is low in fibre content.