25/04/2014 Pet Care Products
When such sand is used for molds for metal casting, the sudden rise in temperature which occurs when the molten metal is run into the mold causes the silica to be cracked and broken into a considerable number of tiny fragments or dust,<a href="http://www.lightcrusher.com/solutions/artificial-sand-making-machine.html">artificial sand making machine</a>, due to the tendency or silica to alter its crystalline form at different temperatures and because of its large rate of expansion. Accordingly natural sand deteriorates with use rapidly and becomes powdery and a mold made from old sand is less porous, so that it is necessary to discard the sand or submit it to a sifting or like process to remove the powdery portion. Where suitable natural sand is available, fresh sand can be added, but where it is not available it has been necessary to reclaim the old sand or bring fresh sand from a considerable distance. Even when the sand is reclaimed it becomes worthless after a certain limited time.
Deterioration of sand under heat produces a powder so fine that it is readily carried into the air and enters the lungs of workmen causing an occupational disease known as silicosis.<a href=" http://www.lightcrusher.com/solutions/limestone-mining-process.html">Limestone production process</a>, silicosis at the present time is a serious menace to life and health of workmen in large foundries and claims for injury from silicosis cause large expense to foundrymen.
My present invention therefore has for its object an artificial foundry sand which is less subject to deterioration from use thereby increasing the length of life of the sand and reducing the menace to the health and life of workmen using it. The invention comprises a method of mak4ing the sand and of making foundry molds therefrom.