In this disclosure, a process of recycling acid, base and the salt reagents required in the Li recovery process is introduced. A membrane electrolysis cell which incorporates an oxygen depolarized cathode is implemented to generate the required chemicals onsite. The system can utilize a portion of the salar brine or other lithium-containing brine or solid waste to generate hydrochloric or sulfuric acid, sodium hydroxide and carbonate salts. Simultaneous generation of acid and base allows for taking advantage of both chemicals during the conventional Li recovery from brines and mineral rocks. The desalinated water can also be used for the washing steps on the recovery process or returned into the evaporation ponds. The method also can be used for the direct conversion of lithium salts to the high value LiOH product. The method does not produce any solid effluent which makes it easy-to-adopt for use in existing industrial Li recovery plants.

The present application is related to a method for controlling heavy metal scouring pollution in mines by using a humified product, which comprises steps of: (1) carrying out mixed fermentation on sludge and hyperthermophiles to breed polar humified groups, and then carrying out mixed fermentation on the fermented material and a native material of humus precursors to induce massive production of humus until the humus content reaches a required standard; and (2) mixing and maintaining the humified product of the sludge reaching the standard with mine soil polluted by heavy metals to remedy the polluted mine.

The present embodiments generally relate to a technology for improving Cu/Mo grade by the addition of cationic polymers as selective depressants for acid insoluble matters, e.g., silicates and/or clays, in the flotation circuit. Various types of cationic polymers are demonstrated to be effective depressants including polyamine, polyDADMAC, and cationic polyacrylamide. Also disclosed are processes for enriching a desired mineral from an ore comprising the desired mineral and gangue, wherein the process comprises carrying out a flotation process in the presence of one or more cationic polymer depressants.

Methods and systems for treating oil sands tailings streams at an elevated pH using lime are disclosed herein. In some embodiments, the method comprises providing a tailings stream including 10-55% solids by total weight, increasing the pH of the tailings stream by combining the tailings stream with lime to produce a lime-tailings mixture having a pH of at least 11.0, and dewatering the lime-tailings mixture to produce a first stream having 10% or less solids by total weight and a second stream having 50% or more solids by total weight. The first stream can correspond to a release water stream, and the second stream can correspond to a cake. The lime slurry can include about 10% lime by total weight, and can comprise lime hydrate, quicklime, or a combination thereof. Dewatering the lime-tailings mixture can include routing the lime-tailings mixture to a centrifuge unit and/or a pressure or vacuum filtration unit.

A treatment process for remediating H.sub.2S and other contaminants in liquids includes: partially filling a closed vessel with a contaminated liquid containing ≥5 ppm H.sub.2S with a head space above the liquid within the vessel where gasses released from the liquid from the liquid collect; separately providing a treatment composition in the head space so that the gasses from the liquid may contact the treatment composition; and permitting the contact between the vapors from the liquid and the treatment composition to continue until a collective concentration of H.sub.2S in the liquid and in the head space is <5 ppm. The treatment composition includes an aqueous solution containing at least one hydroxide compound, a collective concentration of the at least one hydroxide compound in the aqueous solution is in a range of 35-55 weight %, and the aqueous solution constitutes at least 80 weight % of the treatment composition.

A system for separating solids from a fluid mixture includes a vessel including a first chamber to receive a solid-laden fluid mixture, and a second chamber to receive liquids separated from the solid-laden fluid mixture. In certain aspects, at least one eductor is disposed in the first chamber to flow the solid-laden fluid mixture out of the first chamber. In certain aspects, an auger is disposed in the first chamber to move at least solids of the solid-laden fluid mixture out of the first chamber.

A system for recovering fat, oil and grease (FOG) from wastewater has multiple annular flotation zones in a concentric configuration surrounding a central column to create progressively increasing surface areas for FOG and solid particles flotation, and thereby enhance FOG recovery and removal. Each flotation zone is equipped with an independent pressurized micro air and ozone bubbles distribution system. A controlled amount of ozone can be injected into the wastewater along with recirculated effluent and micro-size air bubbles. Upon the release of pressurized air-ozone-water mixture, micro-size bubbles are generated and distributed in each flotation zone to effectively float up FOG and solid particles in the wastewater stream.

The present disclosure relates to processes for treating wastewater such as acid rock drainage. The processes may, for example, comprise subjecting the wastewater to a microbial fuel cell process, neutralizing the acid with a base comprising calcium to produce an aqueous composition comprising calcium ions and subjecting the aqueous composition comprising calcium ions to a biological precipitation process to precipitate the calcium ions as calcium carbonate.

An improved surface evaporation system where droplet size and spray configuration is controlled and modified based upon ambient conditions in order to prevent the spreading of salts and other contaminants outside of a treatment pit or specific area. Water droplet size can be controlled by adjustment of the spray nozzle side. Increasing the nozzle size to increase droplet size results in a reduction of mist travel direction (i.e., drift distance). Reducing the nozzle size decreases the droplet size, and increases drift distance. Similarly, changing the configuration of the spray will affect drift distance. For example, changing the spray direction and height from a vertical spray direction to a flatter, more horizontal direction (with resulting greater area) results in a substantially decreased drift distance. In addition, the system also takes into account the effects of wind speed and direction and humidity. Evaporation modules may use standard spray nozzles, or ultrasonic evaporators.

A compact, portable system and process separates dissolved and suspended solids from water containing high levels of those solids. Gas flotation is used with and oxidant as an initial stage. The resulting foam is dewatered in a fluid conveyance, with the gas being recycled to the flotation column, the foam sent to a holding tank and the water passed through one of a number of filtration vessels having granular filter media. As at least one filtration vessel is kept in operation filtering, another filtration vessel can be backwashed when the flow therethrough is diminished of the fluid level inside rises. Treated water is used for backwashing and provided to a collection conduit.