Preparation of aqueous slurries of calcium dihydroxide. Preparation of aqueous suspensions of calcium hydroxide.

The invention is directed to methods of neutralizing acid drainage from particulate mining waste, comprising consolidating the particulate mining waste to form a consolidated waste solid; adding a hydrophobizing material into the consolidated waste solid, and incorporating into the consolidated waste solid a controlled release base formulation, wherein the controlled release base formulation comprises a particulate base and a controlled release system, and wherein the controlled release base formulation responds to a decrease in pH from acid drainage to release the particulate base, thereby neutralizing the acid drainage.

A method and apparatus for organic waste treatment are disclosed. The method comprises the steps of adding a sorbent to a waste product to form a fluid matrix which may then be subjected to a compressive force to dewater the matrix. Thermal desorption and pasteurisation of the matrix may then be carried out. The sorbent added is draff, which may be obtained as a by-product from various industries, including the distillation of spirits. The apparatus comprises generally a dewatering compressor, but may also include a thermal desorption unit, which may thermally dewater the matrix and pasteurise it.

A method and apparatus for organic waste treatment are disclosed. The method comprises the steps of adding a sorbent to a waste product to form a fluid matrix which may then be subjected to a compressive force to dewater the matrix. Thermal desorption and pasteurisation of the matrix may then be carried out. The sorbent added is draff, which may be obtained as a by-product from various industries, including the distillation of spirits. The apparatus comprises generally a dewatering compressor, but may also include a thermal desorption unit, which may thermally dewater the matrix and pasteurise it.

A sludge dewatering system includes: a concentration apparatus that concentrates sludge while conveying the sludge on a top surface of a filter body; and a dewatering apparatus that subjects the sludge discharged from the concentration apparatus to pressure dewatering. The concentration apparatus includes: a filtering unit that subjects the sludge, which has been added with a first chemical agent, to gravity filtration; a chemical feeder that adds a second chemical agent to the sludge conveyed in the filtering unit; and a moving mechanism that moves the sludge, which has been added with the second chemical agent, in a direction intersecting a conveyance direction of the filter body.

The continuous treatment of a flow of organic liquid sludge is disclosed. Following the optional addition of granular mineral matter to the flow, the sludge is injected at a rate q into a column of air which is at overpressure relative to atmospheric pressure. The air column is circulating at a rate Q>5q in a chamber extending over a specific length in order to create a fluidized bed, in which the sludge is aerolized, between air supply piping upstream of the sludge injection and an outlet reservoir downstream of the fluidized bed, the reservoir being substantially at atmospheric pressure. A flocculant is introduced continuously downstream of the chamber into the fluidized bed in order to aggregate the organic matter before the solid part obtained in this way is separated from the liquid part, the resulting solid part thus being deodorized.

A process for the treatment of thick fine tailings that include constituents of concern (CoCs) and suspended solids is provided. The process includes subjecting the thick fine tailings to treatments including chemical immobilization of the CoCs, polymer flocculation of the suspended solids, and dewatering. The chemical immobilization can include the addition of compounds enabling the insolubilization of the CoCs. Subjecting the thick fine tailings to chemical immobilization and polymer flocculation can facilitate production of a reclamation-ready material, which can enable disposing of the material as part of a permanent aquatic storage structure (PASS).

A process for the treatment of thick fine tailings that include constituents of concern (CoCs) and suspended solids is provided. The process includes subjecting the thick fine tailings to treatments including chemical immobilization of the CoCs, polymer flocculation of the suspended solids, and dewatering. The chemical immobilization can include the addition of compounds enabling the insolubilization of the CoCs. Subjecting the thick fine tailings to chemical immobilization and polymer flocculation can facilitate production of a reclamation-ready material, which can enable disposing of the material as part of a permanent aquatic storage structure (PASS).

Methods are provided for treating intimately dispersed mixtures of water, bitumen, and fine clay particles, such as oil sands mature fine tailings (MFT). Select methods use dissolved silicate ions and a base (alkali), optionally in combination with a biopolymer, to flocculate a slurry. A mixing regime is disclosed involving the addition to MFT of silicate ions in solution and alkali, to initiate aggregation/destabilization of clay particles. Methods are exemplified that provide distinct sediment layers in conjunction with the release of residual bitumen (for example 40-50% of the initial bitumen content). In these exemplified embodiments, a densely packed bottom layer containing ?75 wt. % solids showed high yield stress values (3.5-5.5 kPa) and entrapped little residual bitumen (0.2-0.3 wt. %). The methods accordingly segregate a material suitable for reclamation.

Methods are provided for treating intimately dispersed mixtures of water, bitumen, and fine clay particles, such as oil sands mature fine tailings (MFT). Select methods use dissolved silicate ions and a base (alkali), optionally in combination with a biopolymer, to flocculate a slurry. A mixing regime is disclosed involving the addition to MFT of silicate ions in solution and alkali, to initiate aggregation/destabilization of clay particles. Methods are exemplified that provide distinct sediment layers in conjunction with the release of residual bitumen (for example 40-50% of the initial bitumen content). In these exemplified embodiments, a densely packed bottom layer containing ?75 wt. % solids showed high yield stress values (3.5-5.5 kPa) and entrapped little residual bitumen (0.2-0.3 wt. %). The methods accordingly segregate a material suitable for reclamation.