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STEELMAKING SLAG FOR FERTILIZER USAGE - Coggle Diagram
STEELMAKING SLAG FOR FERTILIZER USAGE
INTRODUCTION
The term “steelmaking slag” refers to the slags from the steel making process using basic oxygen furnace.
Blast furnace slag is a by-product from iron production in blast furnaces, which are fed by a mixture of iron-ore, coke and limestone.
It is because steelmaking slag can be utilized to promote the growth of plants and increase the yield of agricultural products
The use of slag as a raw material for fertilizer or soil amendment still remains relatively small.
However, fertilizers and soil amendments represent an ecofriendly application wherein the advantageous chemical properties of steelmaking slag.
The consumption of slag in blast furnace slag and steelmaking slag according to Nippon Slag Association’s statistics in 2012 respectively.
Civil engineering :1 390 000, 3 470 000
Cement production : 18 220 000, 530 000
Sub-base course material : 3 340 000, 260 000
STEEL MAKING SLAG-CONTAINED ELEMENTS HAVING FERTILIZER EFFECTS
Effects of lime (CaO)
Used to neutralize acid soil
Protect the plant against soil pathogens
Makes the roots strong
Helps promote the absorption of K which important to plant life
Effects of magnesia (MgO)
Neutralize acid soil
Promotes photosynthesis
Effects of phosphoric acid (P2O5)
Promotes plant growth, stooling, root extension, blossoming, and fruit bearing
Effects of manganese (Mn)
Impact the production of chlorophyll
Promote photosynthesis
Effects of iron (Fe)
Making it harmless and reducing damage to the plant roots
Influence the production of chlorophyll
Promote photosynthesis
Effects of silicic acid (SiO2 )
Give a strength to the plants to stand upright
Promote photosynthesis by increase the light receiving capacity
Protect the plant against disease
PROBLEM INVOLVING IN USING STEELMAKING SLAG AS FERTILIZER
It contains very small proportions of N, K, and P which are indispensable for plant life.
It has been given low priority as the farmer considers the cost of fertilizer and the burden of fertilizer application.
MAIN SUBJECT
History of fertilizer made of steelmaking slag
First use of fertilizer made from steelmaking slag as a raw materials is Europe
In 1878, Thosmas has introduced the "Thomas Phosphate Fertilizer"
It is a process of manufacture from ground converter steelmaking slag become widespread
In 1960, Thomas Phosphate Fertilizer has reached to 2 500 000 tons in Germany
In 1918, Thomas Phosphate Fertilizer were introduce to Japan which is Kawasaki Plant the former of Nippon Kokan K.K
However, in the middle 1970, Thomas Phosphate Fertilizer has decrease because a NPK chemical were introduced
NPK Chemical consist of Nitrogen (N), Phosphorus (P) and Potassium (K) which indispensable for the plants to growth
In 1950, Fertilizer Control Law were introduce which farmers can recognized special fertilizer include fish lees, rice bran and compost
Special fertilizer contains iron which consist limonite, slag or iron powder and weathered rock
In 2012, blast furnace were introduced use as raw material for slag silicate fertilizer
The total consumption of blast furnace and steelmaking slag for fertilizer and soil amendment is 260 000 tons
Fertilizer made of Blast Furnace Slag and Steelmaking slag
Steelmaking slag
contains less silicic acid
can be further subdivided into hot-metal pretreatment and basic oxygen furnace slag
Silicic acid used for the plants to easy form
Blast Furnace slag
contain a considerable proportion of Al
Al can easily combines with phosphoric acid in soli which impeder the absorption of phosphoric acid by the plant
CONCLUSION
Steelmaking slag contains Si, Ca, Mn, Mg, Fe, and other components used in fertilisers. Slag phosphate fertilisers have been approved for use.
Steelmaking slag can be used directly as fertiliser, but can also composted by mixing it with animal manure and other materials.
EXAMPLE OF R&D
1) Formation of silica body cells and its effect to suppress brown spot disease
Silica fertilizer is expected to prevent the tiny brown spots that appear on the leaves, ears and stalks of rice plant by forming silica body cells.
The silica body cells formed on the surface of leaves. Thus, the leaves are almost free from germs that cause brown spot disease.
2) Confirmation of fertilizer effect of phosphoric acid and registration of phosphate fertilizer
Dephosphorization slag from the hot-metal pretreatment process of Kashima Works contains about 5% phosphoric acid.
The effects of dephosphorization slag of the Kashima Works is examined as a slag phosphate fertilizer using komatsuna (Brassica Rapa var. perviridis).
The effect is confirmed and Kashima Works is registered as “Phosphate Fertilizer Kashima No 1”.
4) Use of steelmaking slag as a compost
The mix of animal wastes and steelmaking slag can make compost that contains N, P, Ca, Si, Mg, Mn, Fe and others.
The compost temperature of cow manure with addition of steelmaking slag can reach about 70˚C while without steelmaking slag, the temperature can only reach about 58˚C.
The compost with steelmaking slag is stirred up every 10 days, and the temperature is consistent. Thus, it is considered that the progress of the composting can be done in a short period of time.
The compost could be used to cultivate crops by adding steelmaking slag to cow manure as it gave a germination rate of 80% or more.
3) Use of steelmaking slag to improve soil of tsunami-stricken farmland
The deposit of soil brought by the tsunami become acidic because of the sulfuric acid produced by oxidation of pyrite in the soil.
The steelmaking slag fertilizer is applied to the acidified soil of tsunami-stricken paddy field to test-cultivate rice.
The acidic soil is improved by the alkaline CaO that is contained in the slag fertilizer.
The pH of soil was improved from pH 4 to pH 5.5 after the application of the slag fertilizer.
The pH is considered suitable for the cultivation of rice.
SOLUTION IN ORDER TO CONTINUE USING STEELMAKING SLAG AS FERTILIZER
The steelmaking slag needs to be used together with a chemical fertilizer that contains substantial amounts of N, P, and K.
Following the regulation on harmful heavy metal,Hence the process of checking for harmful heavy metals is needed.
ABSTRACT
Blast furnace slag and steelmaking slag have both been used as fertiliser source materials.
Slag silicate fertiliser includes both slag and slag silicate fertilisers. Ca, Si, and Mg are useful components in blast furnace slags.