Kason Corp., Millburn, N.J., has purchased a British manufacturer of sifting, mixing and size-reduction equipment for undisclosed terms. The purchase of Kek-Gardner Ltd., Macclesfield, England, makes Kason the world's largest manufacturer of centrifugal sifting equipment, the company said in a news release. Kason, which also makes screening and fluid bed processing equipment, gains new product offerings with the purchase, including mixers, blenders, reactors and mills.