Silver Anvil receives and processes minerals, mineral concentrates, industrial waste products that contain precious metals, and other resources that may contain precious or recyclable metals. In all cases, the incoming material is first received, assigned a work order number, weighed, and evaluated to define the recovery process that we will use.
Mineral concentrates and ores are first inspected to define their basic characteristics and type of material. Samples are evaluated with a hand lens or microscope to define their general classification. If the material particle size is like sand, it is sent through a Jones Splitter a number of times to ensure that the sample is homogeneous, and then a sample is cut out for fire and XRF assay. If the particle size is greater than sand size, and is not a collectible mineral, the sample is crushed in our 4″ x 6″ crusher and then run through our hammer mill to grind it to sand size and process as described for sand.
Photo of Jones Splitter
At this point in the evaluation the assay data is frequently provided to the client, and options are considered to define the next steps. If concentration is necessary, the sample is prepared for flotation or gravimetric separation using our Model 13 Wilfley laboratory table.
Concentrates with a high metallic content may be taken to our furnaces and melted with fluxes to produce a metal bar for sale to others. All concentrations involve accurate weighing of the starting material with a known assay and evaluation of concentrates middling and tailing.
Sulfide or oxide concentrates are frequently processed using our laboratory DECO sub-A flotation machine. This process defines the values that can be separated by flotation. A mass balance is constructed over the flotation cell like the one in the gravimetric or table study. This provides the basis for the engineer and the client to evaluate this type of separation and decide the best way to recover values from the ore.
Photo of DECO flotation machine
If the material is leachable, it is given a leach test in which a number of solvents at varying concentrations are tested with given quantities of the material in bottles that are tumbled end over end in our tumbling machine. This replicates the procedure used at many mines in which the assayer would place ore and solvent to be tested in old whiskey bottles, cork the bottles and tie them to the head sheave on the mine hoist for one shift. At the end of the shift the bottles were taken down and the contents assayed to define the success of the leach. We evaluate the leaching process in the same way. Mass balances are calculated for each condition. The best conditions are defined for each ore or concentrate being tested.
Pix of bottle tumbler