NOVELTY - Producing gold mining and algae, involves treating first salt water stream to form (i) first purified water stream and (ii) second saline water stream, treating gold ore with first purified water stream to separate gold from gold ore and to form first wastewater, treating first wastewater in wastewater purifying unit comprising algal mat to form e.g. second purified water stream, treating gold ore with second purified water stream to form third saline water stream, feeding third saline water stream to bioreactor, and isolating gold and oil from algal mat.    USE - The method is useful for producing gold mining and algae e.g. Botryococcus, Chlorella species, and Spirulina (all claimed).    ADVANTAGE - The method extract metals out of remaining wastewater.    DETAILED DESCRIPTION - Method for producing gold mining and algae, involves treating first salt water stream having first salt concentration X, where the treating is carried out with at least one of electrodialysis reversal, reverse osmosis or mechanical vapor compression in a first water purification system to form (i) first purified water stream having second salt concentration Y lower than X, and (ii) second saline water stream having salt concentration Z higher than X, treating gold ore with the first purified water stream to separate gold from the gold ore and to form first wastewater, treating the first wastewater in a waste water purifying unit comprising an algal mat to form (i) second purified water stream and (ii) mineral solution, further treating the gold ore with the second purified water stream, treating the second saline water stream in second water purification system connected to the first water purification system and the purified water reservoir to form third saline water stream, feeding the third saline water stream to bioreactor containing algae to form first biomass in the saline water of the first saline water stream and to form first saline biomass stream, feeding the first saline biomass stream to algae growth and harvesting chamber to grow the algae and to form concentrated biomass, feeding the concentrated biomass to the waste water purifying unit and forming filter in the form of an algal mat from the biomass in the waste water purifying unit, and removing the algae mat from the waste water purifying unit and isolating gold and oil from the algal mat. An INDEPENDENT CLAIM is included for gold mining and algae production system.