Abstract:
The present disclosure provides a method for extracting and recovering gold from an aqueous solution, the method including: (1) gold extraction from an aqueous solution through electrocoagulation, in which an electrocoagulation reaction is performed in an electrolytic cell to produce iron hydroxide in-situ, so as to capture gold in the aqueous solution and reduces the gold into gold nanoparticles in-situ; (2) pickling and liquefaction of the precipitated iron sludge, in which the obtained precipitate is dissolved in nitric acid to dissolve iron flocs after washing treatment; and (3) separation and recovery of gold through a nanofiltration membrane system, in which the resulting solution after pickling the precipitated iron sludge is subjected to cut-off treatment using a nanofiltration membrane to separate nano-sized elemental gold from the solution, and then the resultant is washed with water to obtain elemental gold. The extraction and recovery method of the present disclosure has characteristics of high gold extraction efficiency (up to 100%), low cost, simple process, good stability and environmental protection, and can recover high-grade elemental gold (with a comprehensive recovery rate greater than 95%). The method is of an important significance for technical guidance and practical engineering application for the extraction and recovery of gold in various gold smelting and extraction processes.
Abstract:
The present disclosure relates to the field of mineral processing and separation, and in particular, to an underground coal hypergravity field separation system and a separation process. The separation system includes a grading hydrocyclone group, hypergravity field separators, feeding pumps, and conveying pumps. Coal collected underground is graded through a grading hydrocyclone first, then is fed into the hypergravity field separators for separation, and finally, is conveyed to a next link for dehydration through the conveying pumps. The separation system of the present disclosure has less supporting equipment, small floor area, and no complex pipeline, and is suitable for a downhole operation. In addition, the hypergravity field separators can provide a high-strength centrifugal acceleration, which can realize rapid separation of coal gangue particles in a radial direction and a tangential direction, and realize effective separation of fine coal gangue particles.
Abstract:
Drying and separation vibrating fluidized bed for processing wet coal by high-temperature hot air. Wet coal is fed into a vibrating separation chamber connected to a hot air supply duct. The wet coal is vibrated as it is dried and is layered as heat and mass transfer occur between the high-temperature air and the wet coal particles. Hot air enters the bottom of separation chamber through a distribution plate that includes asbestos fiber cloth sandwiched between clamping plates. The wet coal is fed through a feeding distribution device that separates the coal pieces as they enter the separation chamber. After the coal is dried and layered, the heavy and light material exits the separation chamber through two discharge impellers.
Abstract:
Embodiments of the present disclosure provide a pressurized two-product dense-medium separation process for oil shale, and belongs to the field of oil shale industry, in particular to the processing and utilization of oil shale. This process includes: pre-screening a raw oil shale ore through a 25 mm screen; crushing an oversize product, mixing with an undersize product, and separating by a pressurized two-product dense-medium cyclone; and subjecting an underflow and an overflow of the pressurized two-product dense-medium cyclone to dewatering and medium draining respectively to obtain a concentrate and a tailing. The present disclosure has a simple process flow, high separation efficiency and low energy consumption and can reduce the cost of oil refining and achieve better economic benefits.
Abstract:
In the sorting bed, the material to be sorted enters into the pulsating hot air drying stage, and is dried and upgraded under the effect of air flow and high-temperature hot air, the material enters into the pulsating cold wind sorting stage under the effect of scraper conveyors which are parallely arranged up and down inside. The light products and heavy products sorted and layered are respectively conveyed to fine coal and gangue discharging outlets at both ends of the sorting machine. The float and hypostasis at the corresponding discharging ends are respectively discharged by light product discharging wheel and heavy product discharging wheel. At the discharging ends, the material is removed from the sorted light material and heavy material and the medium is purified and recycled to use through subsequent process. The dry sorted air containing vapor and dust is purified and recycled through a subsequent dust removal process.
Abstract:
Provided is a gas-solid fluidized bed dry beneficiation process using a beneficiation density gradient, including: in a dry beneficiation system of a gas-solid fluidized bed, selecting coarse particles and fine particles; placing the coarse particles at a bottom of the dry beneficiation system, and placing the fine particles above the coarse particles, wherein the coarse particles and the fine particles are separated under an initial condition; under an effect of a gas flow, the coarse particles and the fine particles being fluidized to form a high-density beneficiation region and a low-density beneficiation region, respectively, and the coarse particles and the fine particles being mixed at a contact interface to form an intermediate-density beneficiation region; and feeding minerals to be beneficiated from an upper portion of the dry beneficiation system to pass through the low-density beneficiation region, the intermediate-density beneficiation region, and the high-density beneficiation region in sequence.
Abstract:
The present invention is directed towards a process for upgrading lignite comprising: prior to production pre-assess the calorific value of the coal, by selecting a relational expression between a calorific value of lignite and a degree of metamorphism, a moisture content and an ash content thereof based on a ratio of the ash content to the moisture content, pre-assess the calorific value of the coal; combining a relational expression between a production cost and the ash content and moisture content to make a cost budget; determining degrees of deashing and drying; selecting and implementing a lignite ash reduction pretreatment process; and implementing dry sorting first and then drying. The upgrading process has high sorting efficiency, high drying efficiency and low production cost, and meets the requirement for the surface moisture of the raw coal in the dry sorting operation.
Abstract:
A system for separation and drying of moist fine particle coal includes a blast blower, a surge tank, a moisture detection sensor, a control device and two pipelines, wherein the blast blower is communicated with the surge tank; one end of two pipelines which are connected in parallel is communicated with the surge tank, while the other end is communicated with a fluidized bed; a first pipeline includes a first valve, a first flowmeter, an air heater and an electric butterfly valve which are connected in series sequentially, while the second pipeline includes a second valve and a second flowmeter which are connected in series; the moisture detection sensor is arranged in the fluidized bed; and the control device is connected with the blast blower, the first valve, the first flowmeter, the air heater, the second valve, the second flowmeter and the moisture detection sensor.