Abstract: According to one embodiment, a storage device includes a non-volatile memory and a control unit that is electrically connected to the non-volatile memory and that is configured to control the non-volatile memory. The control unit is configured to manage a plurality of management areas obtained by logically partitioning storage area of the non-volatile memory, when a write request is received that includes data for which a valid term has been set, determine, based on the valid term, a first management area from among the management areas, write the data included in the write request to the determined first management area, and when the data written to the first management area is erased, collectively erase all data written in the first management area which includes the data.

Abstract: Cotton-like aggregates (B) including grinding chips from an iron-based metal and a grinding fluid containing oil and water are compression molded for forming a brittle compact (C) having the fibrous grinding chips roughly sheared and excessive water and oil removed therefrom. The brittle compact (C) is crushed for further finely shearing the grinding chips and the resultant grinding chips are mixed with a solidification assistant (D) for producing an iron-based powder material (E) containing the solidification assistant (D).

Abstract: A compactor is provided wherein cuttings delivered to a compaction chamber 33 by a screw conveyor 22 are compacted into a solid product W by operating a hydraulic cylinder 28, and subsequently a gate member 51 disposed at one end of the compaction chamber 33 is opened so as to discharge the solid product W via the one end of the compaction chamber 33. The compaction chamber 33 includes a first cylindrical body 31 and a second cylindrical body 40. The second cylindrical body 40 is removably mounted to one end of the first cylindrical body 31 for facilitating the replacement of the second cylindrical body 40 when the second cylindrical body 40 is worn.

Abstract: A compactor is provided wherein cuttings delivered to a compaction chamber 33 by a screw conveyor 22 are compacted into a solid product W by operating a hydraulic cylinder 28, and subsequently a gate member 51 disposed at one end of the compaction chamber 33 is opened so as to discharge the solid product W via the one end of the compaction chamber 33. The compaction chamber 33 includes a first cylindrical body 31 and a second cylindrical body 40. The second cylindrical body 40 is removably mounted to one end of the first cylindrical body 31 for facilitating the replacement of the second cylindrical body 40 when the second cylindrical body 40 is worn.

Abstract: Cotton-like aggregates (B) including grinding chips from an iron-based metal and a grinding fluid containing oil and water are compression molded for forming a brittle compact (C) having the fibrous grinding chips roughly sheared and excessive water and oil removed therefrom. The brittle compact (C) is crushed for further finely shearing the grinding chips and the resultant grinding chips are mixed with a solidification assistant (D) for producing an iron-based powder material (E) containing the solidification assistant (D).

Abstract: Cotton-like aggregates (B) containing grinding chips from an iron-based metal and a grinding fluid containing oil and water are compression molded thereby forming a brittle compact (C) in which the fibrous grinding chips are roughly sheared and which is removed of excessive water and oil. The brittle compact (C) is crushed for further finely shearing the grinding chips and then, the resultant grinding chips are mixed with a solidification assistant (D) for obtaining powder (E) containing the solidification assistant (D). The powder (E) is solidified by compression molding, thereby forming a water-containing briquette (F). A briquette (A) for use as steelmaking material, which contains powdery pure iron and oil, is obtained by removing the water from the water-containing briquette (F). Without crushing the brittle compact (C), it is also possible to form the briquette (A) for use as steelmaking material by impregnating the brittle compact (C) with the solidification assistant (D) and then drying th compact.