Laiwu Iron Research Articles

山东莱芜铁矿田矿体保存变化兼论地壳升降特征

山东莱芜铁矿田矿体保存变化兼论地壳升降特征

Characteristics, detection, and prevention of karst sinkholes: a case study in Laiwu iron ore mine areas, Shandong Province, China

Karst-related sinkholes are globally recognized geohazards that can be triggered by mining activities. Totally, 136 sinkholes have occurred in the Laiwu iron ore mine area of Shandong Province, China. At the surface, the sinkholes are mostly round or oval shaped. Most are ceiling collapse sinkholes, and they have caused road and building damage, destruction of farmland, connection of surface and ground water, and groundwater contamination. Based on analysis of characteristics on karst sinkhole, geological and hydrogeological conditions, the proposed key factors of the karst collapse in the study area include soil characteristics, degree of karst development in soluble rocks, faults, folds, groundwater dynamic conditions, and human engineering and mining activities. A 300-m-long, 40-m-wide, and 25-m-high cavern was identified with high-density electrical resistivity imaging. Complex solutions were proposed to mitigate karst collapse in the iron ore mining area.

Basic properties of steel plant dust and technological properties of direct reduction

Basic physicochemical properties of the dust from Laiwu Iron and Steel Co. Ltd. were studied. It is found that C, Zn, K, Na, etc. exist in the fabric filter dust, off gas (OG) sludge, fine ash in converter, and electrical field dust in sinter. Among these, OG sludge gives the finest particle, more than 90% of which is less than 2.51 μm. The dust can lead to a serious negative influence on the production of sintering and blast furnaces (BF) if it is recycled in sintering. The briquette and reduction experimental results showed that the qualified strength could be obtained in the case of 8wt% molasses or 4wt% QT-10 added as binders. Also, more than 75% of metallization ratio, more than 95% of dezincing ratio, as well as more than 80% of K and Na removal rates were achieved for the briquettes kept at 1250°C for 15 min during the direct reduction process. SEM observation indicated that the rates of indirect reduction and carbonization became dominating when the briquettes were kept at 1250°C for 6 min.

Analysis of bending on the front end of sheet during hot rolling

Abstract The analysis of bending in finishing rolling was performed. An asymmetrical rolling force model was established, and the upper and lower neutral points were determined. The bending which resulted from the asymmetrical rolling force at the roll gap was studied and related flexibility equations were proposed according to elastic mechanics. Moreover, material mechanics was used to analyze the effects of temperature difference and self-weight on the bending out of the roll gap, and the flexibility equations were constructed. The main factors on bending were summed up, and the bending rule in the rolling could be obtained. In addition practical calculation was made with the production data of ribbon steel from Laiwu Iron & Steel Group Co. Ltd.

The fractal structure of silicon content in molten iron in blast furnace

With ［Si］ time series of No. 1 BF at Laiwu Iron and Steel Group Co. and No.6 BF at Linfen Iron and Steel Group Co. as sample space, and based on rescaled range analysis and method of box dimension, the Hurst exponents of ［Si］ time series of these two BFs and the box dimensions are figured out to be ranging from 0.257 and 0.224 and 1.712 and 1.724, respectively. The complex degree of ［Si］ time series is described, and it is also proved that ［Si］ time series is a long-term negative association fractal time series. With the correlative parameter fixed, the simulated trend was pictured by the theory of iterated function system.

Development of water-atomised alloy steel powders : J.M. Cui et al. (Laiwu Iron and Steel PM Co. Ltd., Shandong Laiwu, China.) PM Industry, vol 11, no 4, 2001, 18–21. In Chinese

Novel, structurally modified potential mimics of the second messenger d-myo-inositol 1,4,5-trisphosphate, based on the biologically active regioisomer d-myo-inositol 1,4,6-trisphosphate, were synthesised. dl-5-O-Benzyl-1,4,6-tri-O-p-methoxybenzyl-myo-inositol was the key intermediate for the preparation of the following compounds: dl-3-deoxy-, dl-3-deoxy-2-O-methyl-, dl-3-O-(2-hydroxyethyl)-, dl-3-O-(3-hydroxypropyl)- and dl-3-O-(4-hydroxybutyl)-myo-inositol 1,4,6-trisphosphate. dl-1,4,6-Tri-O -allyl-5-O-benzyl-myo-inositol was used to prepare dl-2-O-methyl-myo-inositol 1,4,6-trisphosphate. Deoxy-compounds were prepared by reduction of the corresponding tosylated intermediate using Super Hydride. The hydroxyalkyl groups were introduced at the C-3 of myo-inositol using the corresponding benzyl protected hydroxy alkyl bromide via the cis-2,3-O-dibutylstannylene acetal.Methylation and benzylation at C-2 was accomplished using methyl iodide and benzyl bromide, respectively, in the presence of sodium hydride. Deblocking of p-methoxybenzyl groups was accomplished with TFA in dichloromethane and the allyl groups were removed by isomerisation to the cis-prop-1-enyl derivative, which was hydrolysed under acidic conditions to give the corresponding 1,4,6-triol.The 1,4,6-triols were phosphitylated with the P(III) reagent bis(benzyloxy)(diisopropylamino)phosphine in the presence of 1H-tetrazole then oxidised with 3-chloroperoxybenzoic acid followed by deblocking by hydrogenolysis to give dl-2-O-methyl-, dl-3-O-deoxy-, dl-3-O-deoxy-2-O-methyl-, dl-3-O-(2-hydroxyethyl)-, dl-3-O-(3-hydroxypropyl)- and dl-3-O-(4-hydroxybutyl)-myo-inositol 1,4,6-trisphosphate, respectively.