Abstract: Provided is a novel method of producing nickel sulfate from nickel oxide. The method of producing nickel sulfate herein disclosed includes a step of feeding nickel oxide particles and an acid aqueous solution into a pressure resistant container, a step of heating the pressure resistant container in a sealed state to a temperature exceeding 100° C. to obtain a mixed liquid in which nickel oxide is dissolved, and a step of forming nickel sulfate, using the mixed liquid.

Abstract: The stopper is equipped with a stopper main body having a guiding path extending in an axial direction. A stopper member has a flow path extending in the axial direction and is inserted in the guiding path of the stopper main body. A sealing member inserts into the flow path of the stopper member in such a manner as to block the flow path. The stopper member is equipped with, at a position where the sealing member is inserted, a first peripheral wall section fixed in a manner as to extend in the axial direction and a second peripheral wall section separated from the first peripheral wall section in a circumferential direction and extending radially outward along the axial direction.

Abstract: The stopper is equipped with a stopper main body having a guiding path extending in an axial direction. A stopper member has a flow path extending in the axial direction and is inserted in the guiding path of the stopper main body. A sealing member inserts into the flow path of the stopper member in such a manner as to block the flow path. The stopper member is equipped with, at a position where the sealing member is inserted, a first peripheral wall section fixed in a manner as to extend in the axial direction and a second peripheral wall section separated from the first peripheral wall section in a circumferential direction and extending radially outward along the axial direction.

Abstract: A stopper system including a female member having a conduction path extending in an axial direction thereof, which is to be fixed to a fluid inlet/outlet port of a container, a plug detachably engaged with the tip of the female member, a first male member for supplying a fluid into the container, and a second male member for plugging the conduction path of the female member. Fluid is supplied to the container by inserting the first male member into the conduction path of the female member. The female member is plugged by inserting the second male member into the conduction path of the female member. The fluid in the container is discharged to the outside by inserting a fluid discharge pin into the second male member.

Abstract: A stopper system including a female member having a conduction path extending in an axial direction thereof, which is to be fixed to a fluid inlet/outlet port of a container, a plug detachably engaged with the tip of the female member, a first male member for supplying a fluid into the container, and a second male member for plugging the conduction path of the female member. Fluid is supplied to the container by inserting the first male member into the conduction path of the female member. The female member is plugged by inserting the second male member into the conduction path of the female member. The fluid in the container is discharged to the outside by inserting a fluid discharge pin into the second male member.