The present invention aims to develop a technique for efficiently preparing deinked pulp from prints made with UV-curable inks. According to the processes for preparing deinked pulp of the present invention, high quality deinked pulp can be obtained by performing the steps of: disintegrating printed waste paper containing UV prints in water to give a waste paper slurry; and applying a mechanical process to the waste paper slurry using a rotary disintegrator.

A method is disclosed for treating aqueous feed by dissolved gas flotation. The aqueous feed originates from industrial processing of fibrous material, where the aqueous feed includes an aqueous phase and solid particulate material suspended in the aqueous phase. The method includes bringing a flocculant in contact with the aqueous feed, flocculating suspended solid particulate material into flocs and contacting formed flocs with gas bubbles and inducing their flotation in a flotation basin. The flocculant includes a polymer composition having a charge density of at the most 1.7 meq/g dry and the polymer composition includes a cationic synthetic first polymer having a charge density at least 1.0 meq/g dry at pH 2.8, and at least one second polymer obtained by polymerization of (meth)acrylamide, the second polymer being polymerized in presence of the cationic first polymer, where the first polymer has a higher charge density than the second polymer.

A device and method for cleaning contaminated solid-liquid mixtures by removing impurities and contaminants from an aqueous paper fiber suspension by flotation. Apparatus includes a first conduit (2) for a liquid, a second conduit (3) for a solid-liquid mixture, a third conduit (4) connecting first and second conduit (2, 3), a Venturi mixing element (5) with cones (7, 11), having small through-opening into chamber (9) which forms a cavity with small through-opening (12, 13) of the cones; the through-opening of first cone (7) connected with first conduit (2) and the rough-opening connected to second conduit (2), the small through-opening (12) of first cone (7) and the non-conical conduit sections arranged in longitudinal axial alignment, a fourth conduit (6) for conveying gas, wherein the fourth conduit (6) opens to the Venturi mixing element (5), and a fractionator arranged downstream of the second conduit (3) for removing the foam produced by flotation.

A froth flotation arrangement and method for treating mineral ore particles suspended in slurry includes a flotation cell for separating the slurry into an underflow and an overflow and a primary line including at least three flotation cells connected in series, wherein each subsequent flotation cell is arranged to receive the underflow from the previous flotation cell, the flotation cell includes a tank and an impeller within the tank, and the flotation cell includes a gas supply within the tank, the tank includes a volume of at least 200 m3, the flotation cell including a froth collection launder capable to receive the overflow the froth collection launder including a froth overflow lip, the flotation cell having an available froth surface area (A froth), the flotation cell having a pulp area (A pulp), where the pulp area (A pulp) is calculated as an average from the cross sectional areas of the tank at the height (h1) of the impeller. A ratio between a height (h) from a bottom of the tank to the froth overflow lip of the froth collection launder and the diameter (D) of the tank at the height (h1) of the impeller (h/D) is less than 1.5.

The present invention aims to develop a technique for efficiently preparing deinked pulp from prints made with UV-curable inks. According to the processes for preparing deinked pulp of the present invention, high quality deinked pulp can be obtained by performing the steps of: disintegrating printed waste paper containing UV prints in water to give a waste paper slurry; and applying a mechanical process to the waste paper slurry using a rotary disintegrator.

A method is disclosed for treating aqueous feed by dissolved gas flotation. The aqueous feed originates from industrial processing of fibrous material, where the aqueous feed includes an aqueous phase and solid particulate material suspended in the aqueous phase. The method includes bringing a flocculant in contact with the aqueous feed, flocculating suspended solid particulate material into flocs and contacting formed flocs with gas bubbles and inducing their flotation in a flotation basin. The flocculant includes a polymer composition having a charge density of at the most 1.7 meq/g dry and the polymer composition includes a cationic synthetic first polymer having a charge density at least 1.0 meq/g dry at pH 2.8, and at least one second polymer obtained by polymerization of (meth)acrylamide, the second polymer being polymerized in presence of the cationic first polymer, where the first polymer has a higher charge density than the second polymer.

A device and method for cleaning contaminated solid-liquid mixtures by removing impurities and contaminants from an aqueous paper fiber suspension by flotation. Apparatus includes a first conduit (2) for a liquid, a second conduit (3) for a solid-liquid mixture, a third conduit (4) connecting first and second conduit (2, 3), a Venturi mixing element (5) with cones (7, 11), having small through-opening into chamber (9) which forms a cavity with small through-opening (12, 13) of the cones; the through-opening of first cone (7) connected with first conduit (2) and the rough-opening connected to second conduit (2), the small through-opening (12) of first cone (7) and the non-conical conduit sections arranged in longitudinal axial alignment, a fourth conduit (6) for conveying gas, wherein the fourth conduit (6) opens to the Venturi mixing element (5), and a fractionator arranged downstream of the second conduit (3) for removing the foam produced by flotation.

A froth flotation arrangement and method for treating mineral ore particles suspended in slurry includes a flotation cell for separating the slurry into an underflow and an overflow and a primary line including at least three flotation cells connected in series, wherein each subsequent flotation cell is arranged to receive the underflow from the previous flotation cell, the flotation cell includes a tank and an impeller within the tank, and the flotation cell includes a gas supply within the tank, the tank includes a volume of at least 200 m3, the flotation cell including a froth collection launder capable to receive the overflow the froth collection launder including a froth overflow lip, the flotation cell having an available froth surface area (A froth), the flotation cell having a pulp area (A pulp), where the pulp area (A pulp) is calculated as an average from the cross sectional areas of the tank at the height (h1) of the impeller. A ratio between a height (h) from a bottom of the tank to the froth overflow lip of the froth collection launder and the diameter (D) of the tank at the height (h1) of the impeller (h/D) is less than 1.5.

The serial multistage flotation process for eliminating hydrophobic particles from a stream of materials to be treated includes a step of introducing into one stage a layer of materials to be treated, originating either from a higher state or directly from the inlet of the system. There is an aeration step in which air extracted from the lower stages is mixed, diffused and dispersed in the layer of materials to be treated then escapes to the higher stage or to a foam discharge zone. After the aeration step, there is a deaeration step in which air is no longer introduced into the layer of materials to be treated before the departure thereof from one stage and that enables the discharge of the dispersed air to the higher stages or in the case of the highest stage to foam discharge zone. There is also a step of recovering the deaerated material.

Cosmetic agents, in some embodiments in powder form, containing as component (a) at least one polymer comprising at least one structural unit of formula (I) and at least one structural unit of formula (II), in which X denotes a physiologically acceptable cation (in particular Na.sup.+), R.sup.1 denotes a hydrogen atom or a methyl group and R.sup.2 denotes a (C.sub.2 to C.sub.6) hydroxyalkyl group, and as component (b) at least one setting polymer, are suitable for temporarily reshaping keratin-containing fibers. When applied to human hair, for example, an elastic hairstyle with volume was obtained. The hair retained its natural gloss.