there is disclosed a process for the production of tack - free , pourable , filler containing elastomer powder which comprises dispersing a carbon black filler in water ; mixing the thus dispersed carbon black filler with an elastomer latex ; coagulating the thus produced mixture of elastomer latex and carbon black with a two - stage coagulation solution ; partitioning the thus coagulated suspension with a coating resin ; and filtering , washing and drying of the resultant powder , the improvement comprising using as a coating resin a mixture of a styrene / butadiene resin and a styrene / α - methylstyrene or a polystyrene resin wherein the weight ratio of the styrene / butadiene resin to the styrene / α - methylstyrene or polystyrene resin ranges between 4 / 1 and 1 / 4 , said resins containing a mixture of added surfactants , the first being sodium lauryl sulfate and the second being a nonionic isooctyl phenoxy polyethoxy ethanol which contains 10 moles of ethylene oxide in the polyethoxy portion thereof , said mixture of surfactants being added in an amount at least 4 percent by weight and being in a weight ratio of sodium lauryl sulfate to the nonionic surfactant ranging from 2 / 1 to 1 / 2 , and wherein the coagulation temperature ranges from 70 ° to 90 ° c ., and a further improvement of using the coagulating step in a two - step coagulating process , the first being acid / salt and then next using an acid / alum coagulating solution .