The invention provides a method for enriching
rubidium from
magnesium sulfate subtype
salt lake brine. The method comprises the following steps: evaporating the
magnesium sulfate subtype
salt lake brine, stopping
evaporation when the
potassium concentration and the
magnesium concentration in the brine respectively reach 1.5-3wt% and 3-7wt%, and carrying out
solid-liquid separation to obtain a first
solid and a first liquid; the first liquid is diluted and then subjected to
nanofiltration treatment, at least part of magnesium ions and
sulfate ions in the first liquid are removed, and first concentrated water and first
produced water are obtained; the first
produced water is evaporated, concentrated and crystallized,
sodium and
potassium in the first
produced water are separated out in the form of salt, the
rubidium concentration is increased,
evaporation is stopped when the preset
rubidium concentration is reached, and second liquid, namely the rubidium-rich brine is obtained. The method has the advantages of high rubidium comprehensive
recovery rate, full utilization of natural
evaporation, no need of other chemical precipitators, low cost, effective reduction of the yield loss of rubidium in the whole concentration process, realization of effective enrichment of rubidium in the magnesium sulfate subtype brine, and provision of a high-quality
raw material for subsequent separation of rubidium resources.