Conventional treatment and pre-coat polish filtration
The chlor alkali industry frequently uses conventional brine treatment and polish filtration with pre-coat type filters. After saturation, the brine is chemically treated in one or more reactors. Most of the solids are separated in a clarifier where additional residence time is used to further precipitate contaminants (e.g. silica).
Brines produced by solution mining can contain chemicals suppressing the solubility of sulfates (Sulfate Solubility Inhibitors – SSI). Some types of SSI may have an adverse reaction to PTFE Tefflux membranes. If these chemicals are present in the raw brine, then pre-coat filtration (cellulose) is in some cases preferred.
In order to minimize filter aid consumption, the solid load to the pre-coat polishing filters should be kept at a low level. The installation of anthracite pre-clarification filters can assist with that.
The pressure leaf filter generally has a larger footprint and is more capital intensive to install.
ProFilco’s candle type pre-coat filters have the advantage that PTFE Tefflux membranes can be installed for single stage non-pre-coat filtration at a later time.
Candle type back pulse filter
Pressure leaf filter
- The pressure leaf filter generally has a larger footprint and is more capital intensive to install.