Abstract: Abrasive components and clear fluids are separated from an aqueous chemical mechanical slurry used for planarization of semiconductor materials, to permit the reuse of the clear liquid effluent in non-process applications as well as for gray water for irrigation, process cooling water, or as make-up water for a reverse osmosis system, or safe disposal in the industrial waste stream, as desired. A solids detection device determines the concentration of abrasive solids in the aqueous waste effluent stream, and a diverter receives and diverts the entire aqueous waste effluent stream to at least one reuse water collection tank when the abrasive solids concentration is below a desired threshold, and diverts the entire aqueous waste effluent stream to at least one concentrate water collection tank when the abrasive solids concentration is greater than or equal to the threshold. With the additional use of ion exchange, the resulting water stream can be reused in high purity water applications.

Abstract: Abrasive components and water are recovered from an aqueous chemical mechanical slurry used for planarization of semiconductor materials. The slurry effluent is preferably brought to a neutral pH, and cooled to a temperature between about 0.degree. C. and about 15.degree. C. An electrical potential can be applied to the slurry effluent to facilitate agglomeration and separation of particles of abrasive material in the slurry effluent. In one embodiment, the slurry effluent is introduced into a process chamber at ambient temperature and pressure, and supernatant liquid separated from the process chamber is then subjected to a reduction of pressure in a vacuum chamber to cause gas entrapped in the supernatant liquid to bubble to the surface of the supernatant liquid for further separation and collection of water and abrasive particles from the slurry effluent. In another embodiment, slurry effluent is filtered through one or more self-cleaning reversible gross particle filter assemblies.

Abstract: The apparatus for the continuous separation of liquid and relatively fine particles from a liquid slurry includes one or more centrifuge vessels disposed about a longitudinal axis of rotation, and a driver for rotating the centrifuge vessel or vessels. A feed inlet introduces the liquid slurry into each centrifuge vessel, each of which extends at an oblique angle to the axis. A first outlet is provided adjacent to the inner end for the lighter liquid component, and a second outlet is provided adjacent to the outer end for the heavier solid particle component. The inlet of the each centrifuge vessel is preferably located between the first end and the second end, and the second outlet preferably comprises a plurality of solids removal capillary passages connected to a continuous solids removal tube, which can be connected to a source of vacuum to form a vacuum chamber for withdrawing the solids. A supernatant liquid collection chamber is also connected to the first outlet for receiving the supernatant liquid.

Abstract: Abrasive components and water are recovered from an aqueous chemical mechanical slurry used for planarization of semiconductor materials. The slurry effluent is preferably brought to a neutral pH, and cooled to a temperature between about 0.degree. C. and about 15.degree. C. An electrical potential can be applied to the slurry effluent to facilitate agglomeration and separation of particles of abrasive material in the slurry effluent. In one embodiment, the slurry effluent is introduced into a process chamber at ambient temperature and pressure, and supernatant liquid separated from the process chamber is then subjected to a reduction of pressure in a vacuum chamber to cause gas entrapped in the supernatant liquid to bubble to the surface of the supernatant liquid for further separation and collection of water and abrasive particles from the slurry effluent. In another embodiment, slurry effluent is filtered through one or more self-cleaning reversible gross particle filter assemblies.

Abstract: The apparatus for the continuous separation of liquid and relatively fine particles from a liquid slurry includes one or more centrifuge vessels disposed about a longitudinal axis of rotation, and a driver for rotating the centrifuge vessel or vessels. A feed inlet introduces the liquid slurry into each centrifuge vessel, each of which extends at an oblique angle to the axis. A first outlet is provided adjacent to the inner end for the lighter liquid component, and a second outlet is provided adjacent to the outer end for the heavier solid particle component. The inlet of the each centrifuge vessel is preferably located between the first end and the second end, and the second outlet preferably comprises a plurality of solids removal capillary passages connected to a continuous solids removal tube, which can be connected to a source of vacuum to form a vacuum chamber for withdrawing the solids. A supernatant liquid collection chamber is also connected to the first outlet for receiving the supernatant liquid.