Methods and systems for calcining dewatered tailings and/or mine waste are disclosed herein. In some embodiments, the method comprises (i) processing dewatered tailings comprising clay minerals, (ii) calcining the processed tailings to produced calcined tailings, and (iii) altering a composition and/or one or more characteristics of the calcined tailings to produce a cementitious product. Altering the composition can include blending the calcined tailings with one or more additives, such as lime, dolomitic lime, lime kiln dust, argillaceous limestone, limestone, pulverized quicklime, ground calcium carbonate, quicklime, gypsum, natural pozzolans, artificial pozzolans, water, flow aids, or the like.

A reaction device is provided with a first wall that defines an interior in which a stirring mechanism is located. A heat exchanger is at least partly provided on the first outer wall surface facing away from the interior and/or on the stirring mechanism, wherein the heat exchanger has a grate structure, and at least two layers are provided which have a grate structure. Thus, it is possible to transfer heat in a precise and efficient manner primarily by means of thermal radiation in endothermic processes at different temperature levels, in particular pyrolysis, gassing, and reforming processes, and thereby use the exhaust heat for other processes.

A reaction device is provided with a first wall that defines an interior in which a stirring mechanism is located. A heat exchanger is at least partly provided on the first outer wall surface facing away from the interior and/or on the stirring mechanism, wherein the heat exchanger has a grate structure, and at least two layers are provided which have a grate structure. Thus, it is possible to transfer heat in a precise and efficient manner primarily by means of thermal radiation in endothermic processes at different temperature levels, in particular pyrolysis, gassing, and reforming processes, and thereby use the exhaust heat for other processes.

Method and apparatus to facilitate recycling of at least one fraction of bitumen-containing materials. This can be accomplished by dissolving the at least one fraction, for example, maltenes or asphaltenes in roofing shingles, into at least one solvent. In one aspect, the apparatus comprises a dissolution vessel, a tumbler positioned therein, and at least one solvent distributor. The tumbler is configured to facilitate wetting the bitumen-containing materials with solvent. In a second aspect, a system comprises the apparatus, a solid-liquid separator, for example, a vibratory screen, and at least one solvent-fraction separator, for example, a flash drum. The at least one solvent can comprise one or more solvents useful to extract the at least one fraction. In a third aspect, a first fraction is extracted from the bitumen-containing materials with a first solvent composition, then a second fraction is extracted from the remaining bitumen-containing materials with a second solvent composition.

Method and apparatus to facilitate recycling of at least one fraction of bitumen-containing materials. This can be accomplished by dissolving the at least one fraction, for example, maltenes or asphaltenes in roofing shingles, into at least one solvent. In one aspect, the apparatus comprises a dissolution vessel, a tumbler positioned therein, and at least one solvent distributor. The tumbler is configured to facilitate wetting the bitumen-containing materials with solvent. In a second aspect, a system comprises the apparatus, a solid-liquid separator, for example, a vibratory screen, and at least one solvent-fraction separator, for example, a flash drum. The at least one solvent can comprise one or more solvents useful to extract the at least one fraction. In a third aspect, a first fraction is extracted from the bitumen-containing materials with a first solvent composition, then a second fraction is extracted from the remaining bitumen-containing materials with a second solvent composition.

Methods and systems for treating tailings at an elevated pH using lime are disclosed herein. In some embodiments, the method comprises (i) providing a tailings stream comprising bicarbonates and a pH less than 9.0, (ii) adding a coagulant comprising calcium hydroxide to the tailings stream to form a mixture having a pH of at least 11.5 and a soluble calcium level no more than 800 mg/L, and (iii) dewatering the mixture to produce a product having a solids content of at least 40% by weight. In some embodiments, the pH and soluble calcium level of the mixture cause chemical modification of clay materials of the mixture via pozzolanic reactions. In some embodiments, the undrained shear strength of the product increases over a period of time of at least two days.

This disclosure pertains to the use of black liquors from kraft pulp mills as a source of catalysts for the thermochemical conversion of organic matter feedstocks to bio oils. More particularly, some embodiments pertain to integrated kraft pulp mill and thermochemical conversion systems, which include: a Kraft pulp mill comprising a digester for digesting a lignocellulosic material with white liquor to produce pulp and black liquors; a thermochemical conversion subsystem comprising: at least one mixing tank for combining pulping liquors received from the pulp mill with an organic matter feedstock and water to produce a reaction mixture; a reactor vessel for treating the reaction mixture received from the mixing tank at a reaction temperature and pressure suitable for conversion of all or a portion of the organic matter in the reaction mixture into a product mixture comprising a bioproduct and an aqueous stream containing both organic and inorganic compounds; and a depressurizer for depressurizing product mixture received from the reactor vessel; and one or more conveyors for conveying the pulping liquors from the pulp mill to the mixing tank.

This disclosure pertains to the use of black liquors from kraft pulp mills as a source of catalysts for the thermochemical conversion of organic matter feedstocks to bio oils. More particularly, some embodiments pertain to integrated kraft pulp mill and thermochemical conversion systems, which include: a Kraft pulp mill comprising a digester for digesting a lignocellulosic material with white liquor to produce pulp and black liquors; a thermochemical conversion subsystem comprising: at least one mixing tank for combining pulping liquors received from the pulp mill with an organic matter feedstock and water to produce a reaction mixture; a reactor vessel for treating the reaction mixture received from the mixing tank at a reaction temperature and pressure suitable for conversion of all or a portion of the organic matter in the reaction mixture into a product mixture comprising a bioproduct and an aqueous stream containing both organic and inorganic compounds; and a depressurizer for depressurizing product mixture received from the reactor vessel; and one or more conveyors for conveying the pulping liquors from the pulp mill to the mixing tank.

The presently disclosed subject matter relates to an industrial system for processing various plant materials to produce marketable materials. Particularly, the system integrates subcritical water extraction technology and includes a pre-processing module and a two-stage extractor (processing module) with constant control of temperature, pressure, and/or residence time. In some embodiments, the final product of the disclosed system can include feedstock constituents for biofuel production (sugars and/or oil), biochar, raw materials for various industries (such as pulp for manufacturing paper or cellulose for use in various industries). The disclosed system can be modular or non-modular, stationary or mobile, and can include prefabricated elements with programmed automatic or manual operation so that it can be easily moved and/or assembled on site.

The presently disclosed subject matter relates to an industrial system for processing various plant materials to produce marketable materials. Particularly, the system integrates subcritical water extraction technology and includes a pre-processing module and a two-stage extractor (processing module) with constant control of temperature, pressure, and/or residence time. In some embodiments, the final product of the disclosed system can include feedstock constituents for biofuel production (sugars and/or oil), biochar, raw materials for various industries (such as pulp for manufacturing paper or cellulose for use in various industries). The disclosed system can be modular or non-modular, stationary or mobile, and can include prefabricated elements with programmed automatic or manual operation so that it can be easily moved and/or assembled on site.