1 General Provisions
1.0.1 The present Code is formulated with a view to implementing up-to-date, economic and suitable technologies and design in raw material yard of iron & steel plants, thusallowing improved energy efficiency, safety and environmental protection, as well as ensuring normal production.
1.0.2 The present Code is applicable to process design for construction, modernization or expansion of raw material yards in large-or medium-sized iron & steel plants.
1.0.3 The process design of the raw material yard in iron & steel plants shall be aimed to ensure normal production, realize high efficiency and low consumption in the process of raw material handling.
1.0.4 The Code specifies the basic technical requirements for process design of the raw material yard in iron & steel plants. Should any provision hereof be inconsistent with laws, decrees and regulations, the latter shall prevail.
1.0.5 The process design of the raw material yard in iron & steel plants shall also be in compliance with the requirements specified in the prevailing national standards, in addition to the Code.
2 Terms
2.0.1
raw material yard
the place where bulk materials needed by iron & steel plants are stored and handled, equipped with supporting material storage and handling facilities.
2.0.2
stock yard
the area where materials are piled regularly by category.
2.0.3
stock pile
the stack formed by the piled raw materials.
2.0.4
storage time
the ration between the effective storage volume in the yard and the daily average demand from the users for a certain material.
2.0.5
operation coefficient of stock yard
the ratio between the actual (effective) storage volume and the calculated storage volume.
2.0.6
operation rate of system
the proportion of the daily operation time of the raw material yard facilities to meet the production requirement in a day.
2.0.7
receiving
the process in which materials transported by ship, train, truck, pipe, etc.are received and unloaded.
2.0.8
crushing and screening
the process in which the incoming materials are crushed and screened to reach the grain sizes required from the users.
2.0.9
blending
the process in which various raw materials required from the users are blended to reach the target chemical composition. It normally includes three procedures:burdening, longitudinal distribution and transverse reclaiming.
3 General Requirements
3.0.1 The process design of the raw material yard shall meet the demands from the users such as coking, sintering, pelletizing, lime calcination, ironmaking, steelmaking and the captive power plants (shops) , and satisfy process requirements for unloading, loading, stacking, reclaiming, storage, handling and transportation of bulk materials.
3.0.2 The raw material yard should be sized as follows according to the total volume of the incoming raw materials:
1 Small-sized raw material yard:Smaller than or equal to (≤) 3Mt/a.
2 Medium-sized raw material yard:Greater than 3Mt/a, smaller than 10Mt/a.
3 Large-sized raw material yard:Greater than or equal to 10Mt/a, smaller than 30Mt/a.
4 Extra-large raw material yard:Greater than or equal to (≥) 30Mt/a.
3.0.3 The total area of the raw material yard shall cover the floorage within centerline of the roads surrounding the raw material yard.
3.0.4 In the process design for modernization or expansion of a raw material yard, analysis on material flows shall be made, taking into account utilizationof the existing facilities, so as to figure out economic and feasible schemes for modernization or expansion.
3.0.5 The design of the fire protection and prevention for raw material yard shall be made as per the requirements stipulated in the prevailing national standard GB50414 Code for Design of Fire Protection and Prevention for Iron & Steel Metallurgy Enterprises.
3.0.6 The comprehensive utilization of resources for the raw material yard shall be made as per the requirements stipulated in the prevailing national standard GB50405 Code for Design of Comprehensive Utilization of Iron and Steel Industry Resources.
3.0.7 The design of environmental protection for the raw material yard shall be made as per the requirements stipulated in the prevailing national standard GB50406 Code for Design of Environmental Protection of Iron and SteelIndustry.
3.0.8 The daily maximum operation time and daily maximum operation rate of each system of the raw material yard should be as per Table 3.0.8.
3.0.9 The operation coefficient of the blending yard shall be 1, and that of all the other stock yards shall be 0.75 (calculated as one pile) .
3.0.10 All the equipment moving on rails in the raw material yard must be provided with acoustic & visual alarms.Limit switches and end stops shall be installed on both sides of the rails.
3.0.11 Underground structures and underground galleries in the raw material yard should be provided with ventilation and drainage facilities. Dedusting or dust suppression facilities should be mounted at the material transfer points.
4 Receiving
4.1 Basic Requirements
4.1.1 The receiving systems of coking coal and other raw materials should be separated.
4.1.2 The receiving belt conveyor system shall be equipped with weighing scales, metal extractors and sampling devices.
4.1.3 Rainproof shelters shall be provided for underground receiving bins, with bin wall inclination being not less than 60o.
4.1.4 Metallic grates must be provided at the gate of the receiving bins.
4.1.5 Anti-clogging devices shall be provided under the receiving bins.Frozen lump crusher should be provided on the steel grates of the receiving bins in cold regions.
