The present disclosure relates to the field of building materials. In particular, the present disclosure relates to fiber cement production methods and processes that exhibit high solid retention capacity in the dewatering step, providing increased productivity and potentially other process gains related to the lower concentration of solids and additives in the process water.

An apparatus for washing and grading sand includes a first vibrating screen having a deck arranged to receive a feed material. Oversize material passes over the deck of the first vibrating screen for collection as a first product, and undersize material and water are collected in a sump of the first vibrating screen before being pumped to a hydrocyclone. A second vibrating screen receives an underflow from the hydrocyclone upon a deck thereof, with oversize material passing over the deck of the second vibrating screen for collection as a second product. An overflow from the hydrocyclone passes into a settling tank, and a water storage reservoir receives water overflowing from the settling tank while sludge is collected and removed from a lower end of the settling tank. Water is passed from the water storage reservoir to the first and second vibrating screens to wash and fluidise material thereon.

An apparatus for washing and grading sand includes a first vibrating screen having a deck arranged to receive a feed material. Oversize material passes over the deck of the first vibrating screen for collection as a first product, and undersize material and water are collected in a sump of the first vibrating screen before being pumped to a hydrocyclone. A second vibrating screen receives an underflow from the hydrocyclone upon a deck thereof, with oversize material passing over the deck of the second vibrating screen for collection as a second product. An overflow from the hydrocyclone passes into a settling tank, and a water storage reservoir receives water overflowing from the settling tank while sludge is collected and removed from a lower end of the settling tank. Water is passed from the water storage reservoir to the first and second vibrating screens to wash and fluidise material thereon.

A polymer flocculant mixing and dissolving system comprising: a mixing tank (2) in which a solid polymer flocculant is mixed with water used as a solvent; a liquid feed unit (3) for feeding an aqueous solution containing the polymer flocculant from the mixing tank; a regenerative mixer (4A,4B) used to mix and dissolve the polymer flocculant by applying pressure to the aqueous solution containing the polymer flocculant fed from the liquid feed unit while forming a vortex flow; a process channel (61) through which the aqueous solution that has passed through the regenerative mixer is fed to a downstream process; a circulation channel (62) through which the aqueous solution is returned to a position on an upstream side of the liquid feed unit; and a flow rate adjusting unit (6) for adjusting a balance between a flow rate of the aqueous solution flowing through the process channel and a flow rate of the aqueous solution flowing through the circulation channel. The polymer flocculant mixing and dissolving system can stably supply the solution in an amount required in the downstream process.

A method and a process arrangement for improving a solid-liquid separation of solids from a hydrolyzed material formed in an enzymatic hydrolysis of lignocellulosic material, comprising following step: i) adding a flocculant additive to the hydrolyzed material or to a stream separated from the hydrolyzed material to form a mixture, and ii) separating a solid stream and a liquid stream from the mixture by means of a decantation or gravitational separation. Further is disclosed a solid product.

The invention concerns a flocculation formulation. The invention also concerns the treatment of mine tailings in the form of aqueous effluents comprising solid particles. With the method of the invention, it is possible to separate all or part of the water from an aqueous effluent comprising solid particles.

The present invention discloses a process of disposal of tailings in piles stemming from the iron ore processing method, replacing dams, and comprising the steps of thickening the ultra-fine tailings, thickening the sandy tailings, mixing the tailings in the proportion of 80 to 90% by weight of sandy tailings and 10 to 20% by weight of ultra-fine tailings, addition of coagulant, addition of flocculant, filtering the mixture and piling the filtered tailings. Unlike traditional processes, this invention promotes an economically and technically feasible tailing disposal process that can be added to any conventional iron ore concentration plant without the need for any change in the process flowchart.

The present invention discloses a process of disposal of tailings in piles stemming from the iron ore processing method, replacing dams, and comprising the steps of thickening the ultra-fine tailings, thickening the sandy tailings, mixing the tailings in the proportion of 80 to 90% by weight of sandy tailings and 10 to 20% by weight of ultra-fine tailings, addition of coagulant, addition of flocculant, filtering the mixture and piling the filtered tailings. Unlike traditional processes, this invention promotes an economically and technically feasible tailing disposal process that can be added to any conventional iron ore concentration plant without the need for any change in the process flowchart.

An apparatus and method are provided for removing ultra fine sediment suspended in water where the apparatus includes a sheet of open weave textile material, such as jute, that has a polymer flocculant applied thereto to provide a floe curtain for the water to flow through such that the suspended sediment can contact the flocculant and precipitate out of the water. The sheet comprises a top edge and a bottom edge with a top border disposed along the top edge of the sheet and a bottom border disposed near the bottom edge of the sheet. The top border comprises a first plurality of spaced-apart grommets disposed therealong. The sheet further comprises a geotextile tube disposed between the bottom edge and the bottom border. Two or more floe curtains can be placed in a spaced-apart configuration in the water to provide stages of successive filtering as the water flows through the floe curtains.

An automated waste water treatment system includes a collection tank constructed to hold waste water, a first flow line connected to the collection tank to output the waste water from the collection tank, an electrocoagulation unit that receives the waste water and outputs the waste water as coagulated waste water to a flow line, a polymer dosage tank to provide a polymer dosage into the flow line where the polymer dosage mixes with the coagulated waste water to produce and output flocculated waste water. A clarifier connected to the flow line receives the flocculated waste water and produces sludge-free waste water and concentrated sludge, a series of filters to output filter-treated water, and an ultrafiltration system that receives filter-treated water and outputs ultrafiltration-treated water to a reverse osmosis system.