There is provided a particle classification system comprising: a classifier including: a vat defining an interior cavity, a feeder conduit upstream of the interior cavity, an overflow conduit in fluid communication between a top of the interior cavity and outside the vat, an underflow conduit downstream of the interior cavity and a controllable underflow valve fluidly connected to a bottom of the interior cavity, the underflow valve controlled to be either in an open configuration in which the interior cavity is in fluid communication with the underflow conduit or in a closed configuration in which the interior cavity is sealed from the underflow conduit; a feed preparation circuit upstream of the feeder conduit; a rejection circuit downstream of the overflow conduit, and a beneficiation circuit downstream of the underflow conduit. There is also provided a method of classifying fluid-borne particles comprising obtaining a feed containing high-density particles.

There is provided a particle classification system comprising: a classifier including: a vat defining an interior cavity, a feeder conduit upstream of the interior cavity, an overflow conduit in fluid communication between a top of the interior cavity and outside the vat, an underflow conduit downstream of the interior cavity and a controllable underflow valve fluidly connected to a bottom of the interior cavity, the underflow valve controlled to be either in an open configuration in which the interior cavity is in fluid communication with the underflow conduit or in a closed configuration in which the interior cavity is sealed from the underflow conduit; a feed preparation circuit upstream of the feeder conduit; a rejection circuit downstream of the overflow conduit, and a beneficiation circuit downstream of the underflow conduit. There is also provided a method of classifying fluid-borne particles comprising obtaining a feed containing high-density particles.

Methods and systems for treating mined sand to remove an impurity in accordance with the disclosure. An example method mined sand provides mined sand containing the impurity, contacting the mined sand with an aqueous treatment fluid comprising an ethoxylated alcohol and a sulfonic acid derivative, and drying the mined sand; wherein at least a portion of the impurity is removed from the dried mined sand after contact of the mined sand with the aqueous treatment fluid.

Methods and systems for treating mined sand to remove an impurity in accordance with the disclosure. An example method mined sand provides mined sand containing the impurity, contacting the mined sand with an aqueous treatment fluid comprising an ethoxylated alcohol and a sulfonic acid derivative, and drying the mined sand; wherein at least a portion of the impurity is removed from the dried mined sand after contact of the mined sand with the aqueous treatment fluid.

A waste treatment system for separating contaminants including per-fluoroalkyl and poly-fluoroalkyl substances (PFAS) from bulk solid waste (12). A preparation module (9) having a bulk material separator separates oversize material (14) from bulk solid waste (12). A physical separation module (13), located down-stream of the preparation module (9), separates the bulk solid waste (12) based on particle size using physical and/or hydrodynamic and/or density separation techniques. An extraction/chemical separation module (19), located downstream of the physical separation module (13), adds leachate and/or extractant to separate the contaminants from a slurry output from the physical separation module (13), into a fines output and a contaminated water solution. A water circulation system (21) supplies water to the physical separation module (13) and the extraction/chemical separation module (19), the water circulation system including at least one water treatment process, the treated water being recycled and recirculated within the waste treatment system.

Methods and systems for treating mined sand to remove an impurity in accordance with the disclosure. An example method mined sand provides mined sand containing the impurity, contacting the mined sand with an aqueous treatment fluid comprising an ethoxylated alcohol and a sulfonic acid derivative, and drying the mined sand; wherein at least a portion of the impurity is removed from the dried mined sand after contact of the mined sand with the aqueous treatment fluid.

Methods and systems for treating mined sand to remove an impurity in accordance with the disclosure. An example method mined sand provides mined sand containing the impurity, contacting the mined sand with an aqueous treatment fluid comprising an ethoxylated alcohol and a sulfonic acid derivative, and drying the mined sand; wherein at least a portion of the impurity is removed from the dried mined sand after contact of the mined sand with the aqueous treatment fluid.

A method for stabilising a froth or a foam comprising subjecting the froth or foam to vibrations or sound waves having a frequency of less than 20 kHz. The frequency may be less than 1 kHz, for example, a frequency of from 300 Hz to 500 Hz, or from 300 to 450 Hz, or from 300 to 400 Hz. A method for froth flotation is also described.

A method of separating grains of valuable minerals, precious metals, rare-earth metals, precious and semi-precious stones from natural ores in the aquatic environment by means of the phenomenon of adhesion, consecutively covering stages such as: initial separation consisting in sieving fractions up to 5000 μm from alluvial (rubble) ore or crushing primary (rock) ore to a fraction causing the separation of valuable minerals from gangue and where appropriate separating ferromagnetics from ores by means of a known method; forming the suspension by mixing the initially separated fraction of ore with liquid; adsorption of valuable minerals from the suspension on the adhesive coating and also recovering water from the process; and desorption of particles of valuable minerals from the adhesive coating; wherein lanolin or its mixtures with additives are used to form the adhesive coating in the separator, whereby, the content of lanolin in the mixture is not less than 80%.

A method of separating infill material (105) of synthetic turf is disclosed. The infill material (105) comprises sand (155), rubber (165) and fibres (135). The method comprises combining the infill material (105) with water (106) to form an infill slurry (110), and separating one or more of the sand (155), rubber (165) and fibres (135) from the infill slurry (105). A hydrocyclone (104) may be used to separate the infill slurry (105) into a fibre slurry (107) and a sand/rubber slurry (111). An separation unit (200) for carrying out the method is also disclosed.