This disclosure pertains to a process and circuit for producing enhanced manganese-zinc filter cake compositions, and more specifically to a wash process and circuit that produces manganese concentrations of 36-45 wt. % and zinc concentrations of 15-17 wt. % while lowering chloride content to below 3 wt. %. The process and circuit involve sequential washing, drying, repulping, and dewatering of polymetallic filter cakes derived from saline feedstocks, facilitating effective downstream recovery of refined manganese and zinc products.