This was an entirely new process that yielded a very high purity product with extremely low toxicity. The herbicide is temperature sensitive. Temperature must be carefully controlled or the product turns brownish and loses its efficacy. Most dryers had to be ruled out because they use elevated temperatures. The particles tend to stick together, so the product needs continuous and gentle agitation, but because the crystals are subject to dusting, it was necessary to minimize particle attrition. Tests showed that single or double-cone batch drying under vacuum would be too slow to handle the proposed commercial production. Paddle and screw type dryers caused too much product dusting and attrition.

Join for free to read