FIELD: phosphorus production. SUBSTANCE: invention relates to removing harmful metals from dust originated from electrothermal production of yellow phosphorus. Method consists in dissolving dust in phosphoric acid containing at least 25 wt % phosphoric anhydride at temperature above 60 C in aerated reaction zone followed by separating solid residue from phosphoric acid. In preferable embodiment of method, phosphoric acid with molar Na/P ratio less than 0.32 is used, dust dissolving time being 22-26 h. Installation comprises at least one reactor provided with pipelines for feeding phosphoric acid and suspended in water dust, overflow pipeline, heating unit, air-supply pipe, and stirrer. There is also an intermediate container, connected with reactor through overflow pipeline, sludge tank connected with dense filter, belt filter for filtration of sludge from sludge tank, and collector receiving clarified filtrate from dense filter. EFFECT: improved environmental condition.
