5.2　Material Preparation and Supply

5.2.1　For a new converter steelmaking shop，the hot metal should be supplied in a way of one ladle for the whole process，or may also be supplied by mixer type ladle car.

5.2.2　For the hot metal to be charged into furnace，the temperature shall be higher than 1250℃.

5.2.3　The storage and transport of bulk material shall be in accordance with the following provisions:

1　The bulk material storage and transport facility shall include auxiliary material storage and transport facility and ferroalloy storage and transport facility.

2　With reference to the bulk material for slagging in furnace，the particle size shall be 5mm-50mm and the composition shall be in accordance with the current relevant national standard.The lime shall be fresh metallurgical active lime produced by the plant or produced in the adjacent area.

3　As for smelting ferroalloy，qualified material in a particle size of 5mm-50mm shall be purchased and its composition shall be in accordance with the current relevant national standard.

4　When the nominal capacity of converter is 120t or more，the number of underground bins for bulk auxiliary material system should be equal to the number of elevated bins of converter.The number of underground bins for bulk ferroalloy system should match the number of intermediate bins of converter as far as possible.The storage of bulk active lime shall meet the demand for operation in 8 hours or more and the storage of other materials shall not be less than the consumption of 12h.

5　The bulk material feeding system should adopt a belt conveyor system.Mechanical dust collectors shall be installed at material transfer points.

6　The charging system as part of the process equipment below elevated bins of converter shall be provided with enclosing measure and also nitrogen protection device shall be arranged in the system to inhibit the escape of CO gas.

7　The charging system as part of the process equipment below intermediate bins of converter shall be provided with measures of full closure.Mechanical dust collectors shall be installed at material transfer points.

8　The ferroalloy shall be protected from mixing，rainwater and moisture during storage and transportation.

9　The steelmaking shop shall not be provided with the ferroalloy crushing and processing facility.

10　The steelmaking shop may be provided with alloy preheating and drying facility as required.

11　Lime screening facility may be provided for the auxiliary material feeding system in the steelmaking shop as required.

12　Ferroalloy should be stored in and supplied from an internal ferroalloy warehouse of the company.

5.2.4　The scrap charge of converter shall be in accordance with the following provisions:

1　The scrap ratio of furnace charge may be 20%-10% depending on the volume of furnace.The total sulfur and phosphor content shall be lower than 0.1% and the content of inclusions shall be less than 10% in scrap.

2　Before furnace charging，the scrap shall be chosen，classified and processed if required and also shall be stored by classifications.

3　The size and weight of individual piece of scrap shall be in accordance with the current national standard Iron and Steel Scraps（GB 4223）.

5.2.5　It shall be strictly forbidden that any explosive or closed container is mixed in scrap charge.

5.2.6　The scrap bucket shall be designed based on the scrap bulk density of 0.7t/m3-1.0t/m3 and according to the principle of furnace charging with single bucket.

5.2.7　For a new converter steelmaking shop，a separate scrap proportioning shop shall be provided for classified scrap storage，in which the scrap proportioning and bucket charging operation shall be performed according to the requirement.The scrap proportioning shop shall meet the scrap demand for 2-10-day operation.

5.2.8　The ferroalloy for converter steelmaking shall be purchased qualified material with particle size of 5mm-50mm.The steelmaking shop shall not be provided with the crushing and processing facility.The online or offline preheating and drying facility may be provided according to the requirements of steel grades.The composition of ferroalloy shall be in conformity with the current relevant national standard.Ferroalloy should be stored in and supplied from a ferroalloy warehouse.The ferroalloy shall be protected from mixing，rainwater and moisture during storage and transportation.