Patent ID: 6592246
Filing Date: 2003-07-15
Classification: B01D

Abstract:
A method of forming and maintaining for consumption a stock of a slurry derived from a liquid and from a particulate solid material, the method including the steps of:withdrawing the slurry of the liquid and the solid material from the stock of the slurry in a reservoir; directing a stream of additional said liquid or of the withdrawn slurry at a bulk supply of additional said solid material in the form of a heap of the solid material, and on to the solid material of the heap; allowing the stream directed at the heap to drain under gravity from the heap into the reservoir, the stream, while draining from the heap, entraining therein the additional solid material from the heap to increase the specific gravity of the stream and to carry said additional solid material from the heap into the stock of the slurry in the reservoir to increase the specific gravity of the stock of the slurry in the reservoir; and feeding additional said liquid to the reservoir to maintain the volume of the slurry in the reservoir, the method including controlling both the volume of the slurry in the reservoir and the specific gravity of the slurry in the reservoir, the feeding of the additional liquid into the reservoir being initiated, or the feed rate of the additional liquid being increased, in response to decreases in the volume of the slurry in the reservoir associated with the withdrawal of the slurry from the reservoir for consumption of the slurry, and the directing of the stream at the heap of the solid material being initiated, or the flow rate of the stream being increased, in response to decreases in the specific gravity of the slurry in the reservoir associated with the feeding of the additional liquid to the reservoir, thereby both to maintain the volume of the slurry in the reservoir at a desired value, and to maintain the specific gravity of the slurry in the reservoir at a desired value, the feeding of the additional liquid to the reservoir being reduced in rate or discontinued when the desired slurry volume is regained, and the directing of the stream at the heap being reduced in rate or discontinued when the desired specific gravity value is regained.