Target Market: Precious Metal Refining
In the process of manufacturing or recycling high value or hazardous metals, liquids are created that contain particulate metals, metal oxides or other metallic salts. The goal of the manufacturer or recycler is to recover the material’s economic value for sale or reuse or to reduce its cost of disposal. The particulate involved in many of these processes is fairly fine (
Types of Filters Used
Depending on the metal, fluid, temperature and subsequent processing, liquid filter bags, depth and pleated cartridges, and metallic tubular elements and cartridges are used in precious metal refining applications.
Purpose of Filtration
The metallic particulate is of value either as a product (silver, gold, platinum, palladium, etc.) or as a cost of waste. In either case, the purpose of filtration is to effectively remove these particulates from the solution to minimize product loss and waste disposal cost or to meet environmental regulations. In any case, the cost of the filter is inconsequential compared to the cost of the product or its failure to comply with governmental regulations. Another function of the filter is to capture the particulate in such a way that the subsequent processes are facilitated. This includes disposal (volume minimization), backflushing or incineration.
Common Filtration-Related Problems
- Retention Failure - Loss of valuable product or undesirably high level in the filtrate caused by metallic particulate passing through or around the filter
- High Filter Usage - Premature plugging caused by variations in concentration and size of the metallic particulate that requires system shut down or use of a parallel vessel
- High Volume of Waste for Disposal - Insufficient quantity of waste per area; too long, or large horizontal area unutilized resulting in less economical utilization of disposal drums
- Limited Recovery on Backflushing - The surface pore size is too large, the filter has a gradient density, the filter holds the contaminant on the filter or filter supports, its differential pressure has gotten too high, or it is incapable of an appropriate backflush pressure
- Undesirable Contaminant in the Incineration By-Product - Some filters have materials that are either non-combustible or have high combustion temperatures leaving them as a residue with the desired product
- High Incineration Energy Consumption - Some materials require a lot of heat/energy for complete combustion