Abstract: Disclosed is a method for producing battery-grade nickel sulfate by using laterite nickel ore comprising the following steps: sorting the laterite nickel ore to obtain lump ore and sediment ore; crushing the lump ore, and then performing heap leaching, to obtain a crude nickel sulfate solution A; separating the sediment ore to obtain high chromium ore, low iron, high magnesium ore, and high iron, low magnesium ore, and drying, roasting, reducing, and sulfurating the low iron, high magnesium ore to obtain low nickel matte; blowing and performing water extraction on the low nickel matte, and then performing oxygen pressure leaching, to obtain a crude nickel sulfate solution B; performing pressure leaching on the high iron, low magnesium ore to obtain a crude nickel sulfate solution C; and performing extraction on the crude nickel sulfate solutions A, B, and C, and then evaporating and crystallizing, to obtain battery-grade nickel sulfate.

Abstract: The present invention discloses a solenoid valve, it comprises: a movable core, provided with a flange at a lower end thereof; a driving assembly, in which the flange will abut against a bottom portion thereof and can move up against an upper portion thereof within a chamber of the driving assembly; a piston assembly, a central part of which seals a valve port of the solenoid valve, a periphery of which seals an annular chamber formed between the valve port and a valve body of the solenoid valve, the annular chamber being communicated to the inlet connection pipe, the piston assembly being disposed with a conducting hole at a center thereof, which is sealed by the bottom of the driving assembly; when opening the valve port, the flange of the movable core will first be moved to abut against the upper portion of the driving assembly, and then drive the driving assembly to move up in order to open the conducting hole, wherein since flow of fluid from an upper chamber above the piston assembly into an valve body