The invention provides a method for separating
copper and
arsenic from
copper-
arsenic slag. The method comprises the steps that the
copper-
arsenic slag is subjected to pressurized oxidation leaching in a
sodium hydroxide system, the arsenic and a small amount of heavy
metal ions enter a solution, and the remaining copper,
antimony and lead enter oxidated and leached
slag after being subjected to oxidation; the heavy
metal ions which enter the pressurized and oxidated solution are subjected to
sulfide precipitation, and a
sodium arsenate solution obtained is subjected to
crystallization dearsenifying and then returns to the alkaline pressurized oxidation leaching
system; the copper,
antimony, lead and other elements which enter the oxidated and leached slag are subjected to leaching utilizing
sulfuric acid, the copper can be subjected to subsequent electrodeposition for extraction of the copper after entering the solution, and the
antimony and lead are reserved in acid-leached slag and subjected to subsequent separation and
recovery. By means of the pressurized oxidation leaching, the efficient leaching of the arsenic from the copper-arsenic slag can be achieved, the
leaching rate of the arsenic reaches 96% or above, and furthermore, the subsequent acid leaching of the copper is facilitated through the further oxidation of the copper in the copper-arsenic slag; the
precipitation rate of the heavy
metal ions, including the copper, antimony and lead reaches 85% or above; and the method for separating the copper and the arsenic from the copper-arsenic slag is lower in corrosivity to equipment, friendly to environment and low in labour intensity.