Process for making granular material

A process for making a granular absorbent material from waste paper, comprising the steps of:

• (a) forming a slurry from waste paper, said slurry including water, kaolin clay and cellulose fibers suitable for papermaking;
• (b) screening the slurry so as to produce an accept stream containing fibers suitable for papermaking and to produce a reject stream including water, kaolin clay and cellulose material;
• (c) clarifying the reject stream by flotation to produce a concentrated stream;
• (d) dewatering the concentrated stream to form a filter cake having a solids content of between about 35 and 45 percent;
• (e) heating the reject stream to pasteurization temperature before the dewatering step;
• and
• (f) breaking up the filter cake to produce granular material.

A process for making a granular absorbent material from waste paper, comprising the steps of:

• (a) forming a slurry from waste paper, said slurry including water, kaolin clay and cellulose fibers suitable for papermaking;
• (b) screening the slurry so as to produce an accept stream containing fibers suitable for papermaking and to produce a reject stream including water, kaolin clay and cellulose material;
• (c) clarifying the reject stream by flotation to produce a concentrated stream;
• (d) dewatering the concentrated stream to form a filter cake having a solids content of between about 35 and 45 percent;
• and
• (e) heating the concentrated stream between said clarifying step and said dewatering step to a temperature greater than about 160.degree. F.

A process for producing granular absorbent material, comprising:

• (a) preparing a pulp slurry from wastepaper including kaolin clay and cellulosic material;
• (b) separating the pulp slurry into a first stream which contains papermaking fibers and a second stream which is in the form of a slurry including kaolin clay and cellulose fines;
• (c) cleaning and deinking the papermaking fibers in the first stream for subsequent use in a papermaking operation while producing an effluent stream;
• (d) conducting the second stream and the effluent stream to a clarifier to produce a concentrated stream of solid components including kaolin clay;
• (e) removing water from the concentrated stream of solid components containing kaolin clay to produce a filter cake;
• (f) treating the filter cake to produce absorbent material containing kaolin clay;
• and
• (g) drying the granular material containing kaolin clay to produce granular material having a solids content of at least 90%.

A process for producing granular absorbent material, comprising:

• (a) preparing a pulp slurry from wastepaper including kaolin clay and cellulosic material;
• (b) separating the pulp slurry into a first stream which contains papermaking fibers and a second stream which is in the form of a slurry including kaolin clay and cellulose fines;
• (c) cleaning the papermaking fibers in the first stream for subsequent use in a papermaking operation;
• (d) clarifying the second stream to produce a concentrated stream of solid components including kaolin clay by conveying the second stream to a flotation clarifier in which solid components of the second stream float upwardly for removal from the flotation clarifier;
• (e) removing water from the concentrated stream of solid components containing kaolin clay to produce a filter cake;
• (f) treating the filter cake to produce absorbent material containing kaolin clay;
• and
• (g) drying the absorbent material containing kaolin clay to produce granular material having a solids content of at least 90%;
• and
• (h) applying heat to the concentrated stream of solid components before the treating step to achieve pasteurization of the concentrated stream.

A continuous process for making a granular absorbent material from waste paper containing kaolin clay and papermaking fibers, comprising the steps of:

• (a) forming a pulp slurry from waste paper containing kaolin clay and paper making fibers;
• (b) screening the slurry so as to produce an accept stream containing papermaking fibers and to produce a reject stream including water and kaolin clay;
• (c) conducting the reqject stream to a flotation clarifier in a continuous stream to produce a concentrated stream having a solids content of about 3-9 percent;
• (d) dewatering the concentrated stream continuously to form a filter cake having a solids content of between about 35 and 40 percent;
• (e) continuously breaking up the filter cake from the dewatering step to form granular material without further dewatering of the filter cake;
• and
• (f) subsequently drying the granular material.

A process for making a granular absorbent material from waste paper containing kaolin clay and papermaking fibers comprising the steps of:

• (a) providing a stream of water containing solids from waste paper, the solids including kaolin clay, and the stream having a solids content of less than 1.5 percent;
• (b) clarifying the stream by flotation to produce a concentrated stream having a solids content of 3 to 9 percent;
• (c) dewatering the concentrated stream to form a filter cake having a solids content of 35 to 40 percent;
• (d) conveying the filter cake to a pin mixer of the type having a cylindrical shell and a rotary shaft with radial pins;
• (e) partially filling the shell with filter cake;
• (f) imparting rotation to the rotary shaft to cause the filter cake to pass through the shell from one end to the other while forming granules of a selected size range;
• and
• (g) drying the granules from the pin mixer.

A continuous process for making granules or particles from waste paper containing kaolin clay and papermaking fibers comprising the steps of:

• (a) forming a pulp slurry from waste paper containing kaolin clay and papermaking fibers;
• (b) screening the pulp slurry so as to produce a main stream containing papermaking fibers and to produce a reject stream containing at least water and kaolin clay;
• (c) clarifying the reject stream by flotation to produce a concentrated stream;
• (d) dewatering the concentrated stream to form a filter cake having a solids content of 35 to 40 percent;
• (e) selectively conveying the filter cake along one of a plurality of paths;
• a first one of the paths including a pin mixer in which the filter cake is broken up without further dewatering and form which wet granules and including a dryer for drying the granules from the pin mixer to a solids content of at least 90 percent to form absorbent granules;
• and a second one of the paths, includes using a conveyor to break up the filter cake forming particles having a solids content of 35 to 40 percent and discharging the particles having a solids content of 35 to 40 percent.