This patent describes the use of barium sulfate as filler for
thermosetting and thermoplastic plastics, elastomers, sealants,
adhesives, fillers, varnishes, paints, paper, glass and as substrate for
colored pigment formulations as well as for single-layer or multilayer
coatings consisting of metal oxides, metal oxide mixtures and/or metal
compounds, as a nucleus of crystallization for lead sulfate in the
negative electrode paste of lead accumulators and as an X-ray contrast
medium, the barium sulfate being produced by a continuous process wherein
a barium salt solution and a sulfate solution are simultaneously and
continuously brought together in equimolar quantities in a precipitating
suspension at a temperature of 30 to 90.degree. C., with constant
stirring, the precipitating suspension is withdrawn continuously in a
steady volume and the barium sulfate precipitate is filtered, washed and
optionally dried, wherein the barium salt solution has a concentration of
0.1 to 0.8 Ba.sup.2+ mol/l and the sulfuric acid has a concentration of
0.1 to 2.0 SO.sub.4.sup.2- mol/l, and the flow rate and stirring speed
are controlled, at a constant precipitation volume, in such a way that a
pH value of 1 to 5 is obtained in the precipitating suspension, and the
lamellar barium sulfate particles produced as result of the precipitation
are 0.1 to 50 .mu.m wide, 0.1 to 50 .mu.m long and 0.1 to 2 .mu.m thick
and the needle-shaped particles produced as result of the precipitation
are 1 to 50 .mu.m long and 0.1 to 2 .mu.m thick, the ratio of length or
width to the thickness being 3:1 to 500:1.