NOVELTY - Potash processing system (200) comprises concentrator to heat brine (19) containing potash and produce precipitated sodium chloride, water vapor and potash-concentrated brine; crystallizer for producing potash saturated brine and potash-precipitated slurry from potash-concentrated brine; potash centrifuge for producing potash paste from potash-precipitated slurry; heat pump for compressing working fluid, and condenser heat exchanger to transfer heat from working fluid to brine; expansion valve; and evaporator to evaporate working fluid; and condense water vapor to produce condensate (23).    USE - For extracting potash from brine containing potash without the use of water-consuming evaporation ponds or additional chemicals.    ADVANTAGE - The system uses the energy efficiency of vapor-compression cycle to heat or cool the salt-potash brine; which can be operated at unique thermodynamic operating pressures, this increases the pressure across compressor and temperature differences across the heat exchangers; thus minimizes power consumption and depreciation cost of heat exchangers and pressure vessels. The brine may be entirely heated through heat exchangers from the vapor-compression cycle without the need to burn natural gas or other hydrocarbons. Using water as the working fluid has the advantage of decreasing the capital cost and potential environmental impact of the overall system. The condenser heat exchanger can recapture heat (e.g. reduce operating cost) generated from compressing the working fluid by boiling the potash brine to produce potash-concentrated brine and water vapor. The evaporator heat exchanger, in turn, may recapture the water vapor (e.g. reduce the environmental impact) by condensing the water vapor from the boiling brine and turning the working fluid into saturated vapor before being compressed again. The processing system is mobile, which can be built in factory on transportable skids, hauled to a well site for an indefinite period of time, and then moved to new sites. The system is scalable to the needs of specific well sites. Modularity enables the concept of reducing upfront investment and risk associated with large-scale central plant installations.    DETAILED DESCRIPTION - Potash processing system (200) comprises concentrator to receive brine (19) containing potash from brine source (4) and heat the brine to produce precipitated sodium chloride (NaCl), water vapor (31), and potash-concentrated brine; crystallizer for receiving potash-concentrated brine and precipitate potash from potash-concentrated brine to produce potash saturated brine and potash-precipitated slurry (21); potash centrifuge configured to receive potash-precipitated slurry; and separate precipitated potash from potash-precipitated slurry to produce potash paste; heat pump having compressor to compress a working fluid; a condenser heat exchanger (33) to transfer heat from working fluid to brine in concentrator; expansion valve to expand working fluid; and evaporator heat exchanger configured to evaporate working fluid; and condense the water vapor to produce condensate (23). An INDEPENDENT CLAIM is included for processing potash from salt-potash brine involving compressing a working fluid and transferring it to a condenser heat exchanger; transferring brine to concentrator; heating the brine in concentrator with heat from condenser heat exchanger to produce precipitated NaCl, water vapor, and potash-concentrated brine; transferring the potash-concentrated brine to a crystallizer; precipitating potash from the potash-concentrated brine in the crystallizer to produce potash-saturated brine and potash-precipitated slurry; transferring the potash-precipitated slurry to a centrifuge; separating precipitated potash from the potash-precipitated slurry in the centrifuge to produce potash paste; expanding the working fluid through an expansion valve; and cooling the working fluid in evaporator heat exchanger to produce condensate.    DESCRIPTION OF DRAWING(S) - The figure shows potash processing system.    Brine source (4)    Brine (19)    Potash-precipitated slurry (21)    Condensate (23)    Water vapor (31)    Condenser heat exchanger (33)    Vapor-compression cycle (105)    Processing system (200)