Abstract: An air duct component includes first and second volute members arranged oppositely in a cross section perpendicular to an axis of a cross-flow impeller. An inner end of the first volute member includes a volute tongue. A cross-flow air duct formed between the first and second volute members includes a middle air duct section and an end air duct section arranged along an axial direction of the cross-flow impeller. The middle air duct section includes a middle air outlet duct located downstream of a vertical line that passes through the volute tongue and is perpendicular to the second volute member. The end air duct section includes an end air outlet duct located downstream of the vertical line. A cross-sectional area of the middle air outlet duct is larger than a cross-sectional area of the end air outlet duct.

Abstract: Provided are a preparation method for a propylene epoxidation catalyst, and a use thereof. During the preparation, an alkoxide solution of a prepared active component and a silica gel support are mixed, then a rotary evaporation treatment is performed on the mixture to remove a low-carbon alcohol to obtain a catalyst precursor, and then the obtained catalyst precursor is subjected to calcination and silylation treatments to obtain the propylene epoxidation catalyst. The catalyst is prepared in a simple process, can be applied to the chemical process of preparing propylene oxide by propylene epoxidation, has high average selectivity to propylene oxide, and has industrial application prospect.

Abstract: Provided are a device and a method for extracting a terrain boundary, including: a grid creating module configured to divide a region which is determined based on measured contour line data of a target terrain, to form a regular grid including multiple grid units; a data analyzing module configured to assign a first standard value or a second standard value to each of the multiple grid units based on the number of elevation points included in the grid unit, to form a final grid region, where the final grid region is a region including all grid units having the first standard value; and a boundary extracting module configured to extract a terrain boundary based on the final grid region.

Abstract: A method and device for filling invalid regions of terrain elevation model data are provided by the present disclosure. The filling method includes obtaining an isolated invalid grid in first terrain elevation model data, the invalid grid being a grid without a valid elevation value; interpolating an elevation value of the isolated invalid grid by using elevation values of valid grids around the isolated invalid grid, to obtain data-interpolated first terrain elevation model data; obtaining invalid patches in the data-interpolated first terrain elevation model data, each of the invalid patches being a region consisting of at least two adjacent invalid grids; and interpolating elevation values of the invalid grids in the invalid patches by using a further terrain elevation model data other than the first terrain elevation model data, to fill the invalid regions of the first terrain elevation model data.

Abstract: Provided are a device and a method for extracting a terrain boundary, including: a grid creating module configured to divide a region which is determined based on measured contour line data of a target terrain, to form a regular grid including multiple grid units; a data analyzing module configured to assign a first standard value or a second standard value to each of the multiple grid units based on the number of elevation points included in the grid unit, to form a final grid region, where the final grid region is a region including all grid units having the first standard value; and a boundary extracting module configured to extract a terrain boundary based on the final grid region.

Abstract: A method and device for filling invalid regions of terrain elevation model data are provided by the present disclosure. The filling method includes obtaining an isolated invalid grid in first terrain elevation model data, the invalid grid being a grid without a valid elevation value; interpolating an elevation value of the isolated invalid grid by using elevation values of valid grids around the isolated invalid grid, to obtain data-interpolated first terrain elevation model data; obtaining invalid patches in the data-interpolated first terrain elevation model data, each of the invalid patches being a region consisting of at least two adjacent invalid grids; and interpolating elevation values of the invalid grids in the invalid patches by using a further terrain elevation model data other than the first terrain elevation model data, to fill the invalid regions of the first terrain elevation model data.

Abstract: A method to recover gold lost in roaster calcine-leach tailings, due to the formation of cyanide refractory compounds or morphologies during the roasting process. The process can include acid leaching of magnetic concentrate from roaster leach tailings, combining the acid leach slurry to the pre-acidulation tank for pressure oxidation feed, acid pressure oxidation of the pressure oxidation feed, and recovery of gold.

Abstract: The present disclosure is directed to a process for recovering a precious metal from a pregnant leach solution using a resin extractant. The precious metal is eluted from the loaded resin using an eluant comprising trithionate. The barren resin is contacted with a sulfide, bisulfide, and/or polysulfide to convert sorbed trithionate to thiosulfate. The desorbed thiosulfate is contacted with an oxidant and converted to trithionate for eluant recycle.

Abstract: A method to recover gold lost in roaster calcine-leach tailings, due to the formation of cyanide refractory compounds or morphologies during the roasting process. The process can include acid leaching of magnetic concentrate from roaster leach tailings, combining the acid leach slurry to the pre-acidulation tank for pressure oxidation feed, acid pressure oxidation of the pressure oxidation feed, and recovery of gold.

Abstract: The present disclosure is directed to a process for recovering a precious metal from a pregnant leach solution using a resin extractant. The precious metal is eluted from the loaded resin using an eluant comprising trithionate. The barren resin is contacted with a sulfide, bisulfide, and/or polysulfide to convert sorbed trithionate to thiosulfate. The desorbed thiosulfate is contacted with an oxidant and converted to trithionate for eluant recycle.

Abstract: A method and apparatus for precipitating manganese from acidic sulfate solutions, and more specifically from zinc leach solutions, without removing zinc. A zinc- and manganese-containing solution is treated with an SO2—O2 gas mixture at the appropriate pH and temperature, thereby causing manganese to precipitate as a trivalent and/or tetravalent manganese hydroxides and/or oxides that report to the leach residue or are removed separately from solution by solid/liquid separation. These trivalent and/or tetravalent manganese compounds may be used as oxidants in other parts of the leach circuit.