Research on Key Points of Design of Standard Plants in Modern Industrial Parks Under the Background of Promoting the Development of New Quality Productive Forces

With the progress of science and technology and the acceleration of industrialization,the modern industrial park is an important carrier of industrial development.The importance of its standard plant design has become increasingly prominent.With the development of new quality productive forces as the background,this research deeply discusses the key points of standard plant design in modern industrial parks.This paper uses literature review and case analysis to systematically analyze the important role of standard plant design in developing new quality productive forces in modern industrial parks and puts forward suggestions for optimizing design.It is found that the rationality,intelligence,and environmental protection of plant design are the key factors affecting the development of new quality productive forces.The paper summarizes the core points of modern industrial park standard plant design to provide a reference for the future development of related industries.

Preparation of ferronickel from nickel laterite via coal-based reduction followed by magnetic separation

The sticking phenomenon between molten slag and refractory is one of the crucial problems when preparing ferronickel from laterite ore using rotary hearth fulnace or rotary kiln processes. This study aims to ameliorate sticking problems by using silicon dioxide （SiO2） to adjust the melting degree of file briquette during reduction roasting. Thermodynamic analysis indicates that the melting temperature of the slag gradually increases with an increase in the SiO2 proportion （SiO2/（SiO2 ＋ A1203 ＋ MgO） mass ratio）. Experimental validations also prove that the briquette retains its original shape when the SiO2 proportion is greater than 75wt%, and sticking problems axe avoided during reduction. A ferronickel product with 8.33wt% Ni and 84.71wt% Fe was prepared via reductive roasting at 1500~C for 90 min with a SiO2 proportion of 75wt% and a C/O molar ratio of 1.0 followed by dry magnetic separation; the corresponding recoveries of Ni and Fe reached 75.70% and 77.97%, respectively. The micro stxucture and phase txmlsformation of reduced briquette reveals that the aggregation and growth of ferroinckel particles were not significantly affected after adding SiO2 to the reduction process.

Technological analysis of the reasonable pulverized coal injecting rate of the BF process

This study discusses the key factors limiting the rate of pulverized coal injection （PCI） in blast furnaces （BF）, while the practice and experiences of Baosteel＇ s BF production with high productivity and low fuel consumption are also analyzed. A methodology based on technological analysis for achieving a reasonable PCI rate is proposed. It is emphasized that high BF productivity should be realized at the maximum bosh gas index based on a higher blast temperature and the excellent quality of raw materials,as well as a high blast volume and melting strength.

Behaviour of non-ballast pre-stressed and precast track structures in high speed railway based on multiscale finite element model

In order to make further study on the mechanical property of CRTSIII type slab non-ballast track structures,which was self-designed in China,based on the method of the multiscale finite element model(FEM),the traditional FEM of slab non-ballast track structures was improved.The multiscale FEM of CRTSII type slab nonballast track structures was established based on the general finite element program ABAQUs.Then the comparative calculation was made between various FEMs,showing that the high solution precision,fast modelling speed and high solution efficiency could be obtained.Therefore,the multiscale FEM was suitable for the parametric study on mechanical behaviour of CRTSII type slab non-ballast track structures,and then the key influence factor and constructions could be optimized.

Effect of Al content on modification behavior of non-metallic inclusions in high-strength steel treated with rare earth

The influence of Al content(0.0053,0.0171,and 0.0578 wt.%)on the modification behavior of non-metallic inclusions in 20CrMoVTiB steel treated with rare earth elements was studied through high-temperature experiments and thermodynamic simulation.The results showed that the modification products varied with the Al content in steel under 0.01 wt.%of Ce addition.The formation sequence of typical rare earth inclusions in steel with the increase in Al content was Ce_(2)O_(3)→CeAlO_(3)→CeAl_(11)O_(18),and the final stable products were highly Al content dependent.When the Al content was 0.0053 wt.%,the stable phase in steel was Ce2O3;while the[Al]reached 0.0171 wt.%,the stable phase became CeA1O_(3).As the A1 content reached 0.0578 wt.%,CeAl_(11)O_(18) became the stable phase.As a result,increasing the Al content could inhibit the precipitation of Ce_(2)O_(3) inclusions in steel while promote the formation of CeAIO3 and CeAl_(11)O_(18) inclusions.In addition,both Ca treatment and Ce treatment could effectively refine the size of inclusions in steel by changing their types.However,the feeding amount of Ca wire into molten steel should be appropriately reduced under the condition of adding Ce simultaneously,which is expected to be beneficial for an improved Ce treatment effect.

Structure and properties of AZ31B magnesium alloy sheets processed by repeatedly unidirectional bending at different temperatures

Repeatedly unidirectional bending(RUB) was applied to the magnesium alloy sheet to improve the basal texture.The effect of RUB temperature on resulting structure and room temperature properties was investigated.The texture components of the sheet undergoing RUB at recovery temperature were similar to those of the sheet undergoing RUB at room temperature(RT).As the RUB temperature increased to above recrystallization temperature,the texture components became more disperse and the pyramidal components increased.With the increase of RUB temperature,the grain size near the surface of the sheets undergoing RUB tended to grow up.When the sheets were processed by RUB at medium-high temperature followed by annealing at 533 K,the yield strength and fracture elongation were lower than those of the cold rolled sheet;however,the Erichsen value was slightly higher than that of the cold rolled sheet.The sheet undergoing RUB at RT followed by annealing at 533 K represented the best mechanical properties.

Textural Evolution of AZ31B Magnesium Alloy Sheets Undergoing Repeated Unidirectional Bending at Room Temperature

In this paper, repeated unidirectional bending （RUB）, was applied to improve the texture of AZ31B magnesium alloy sheets so as to enhance their stamping properties. The samples undergoing RUB were annealed at different temperatures. The mechanical properties, formability, textural components and microstructure of the samples before and after RUB were characterized and compared. It was found that the basal textural component was reduced dramatically by RUB, and that （1212） and （1211） textural components appeared. Annealing has a great effect on the mechanical properties of samples undergoing RUB. The plasticity and stamping formability of samples were greatly improved by RUB and annealing at 260℃ for 1 h, and elongation to fracture and Erichsen value were increased to 38% and 67%, respectively.

An inversion algorithm for general tridiagonal matrix

An algorithm for the inverse of a general tridiagonal matrix is presented. For a tridiagonal matrix having the Doolittle factorization, an inversion algorithm is established. The algorithm is then generalized to deal with a general tridiagonal matrix without any restriction. Comparison with other methods is provided, indicating low computational complexity of the proposed algorithm, and its applicability to general tridiagonal matrices.

Effect of Calcium Aluminate Cement Addition on Properties of Al_(2)O_(3)-SiO_(2) Based Gunning Mixes

Al_(2)O_(3)-SiO_(2) based gunning mixes were prepared with electric porcelain waste,silica fume,bauxite,quartz powder,and calcium aluminate cement(CAC)of different additions as raw materials firing at different temperatures to research the effect of the CAC addition on their phase change and properties.The results show that:from theoretical analysis of the phase diagram,with the CAC addition increasing from 8%to 14%,anorthite increases from 40.0%to 77.7%,by mass.With the rising CAC addition,the permanent linear change on heating of specimens increases;for the specimens dried at 110℃or hot-treated at 1000℃,the bulk density and the mechanical properties increase,and the apparent porosity decreases;and for those hottreated at 1300℃,the bulk density and the mechanical properties firstly increase,and then decrease,while the apparent porosity shows an opposite trend.Taking into account the phases at high temperatures and the properties,the optimal CAC addition of Al_(2)O_(3)-SiO_(2) based gunning mixes is 12%.

Determination of Hexavalent Chromium in Refractories by Diphenylcarbazide Spectrophotometry

The high chrome refractories were crushed,ground into powder and sampled.A mixture solution of sodium carbonate and sodium hydroxide was used to extract the powder samples.The extracted solution from the samples was mixed and reacted with diphenylcarbazide to form colored substance.The hexavalent chromium content in the samples was determined by spectrophotometry.The effects of the extracting conditions,the color reagent reaction conditions,the sample mass,the working curve and the trivalent chromium coexistence on the results were studied.The experiments about determination,recovery and precision were carried out.The relative standard deviation was less than 5%and the recovery rate was 98%-104%.

Real-Time Slab Quality Diagnosis and Analysis System Based on Solidification Mechanism

According to the two types of slab defects （surface crack and internal crack）, a real-time slab quality diag nosis and analysis system named CISDI_SQDS ONLINE R2011 was developed based on heat transfer and solidifica tion simulation, stress and strain calculation as well as metallurgical process analysis about continuous casting, com- bined with expert knowledge database for specific casting events. The respective crack formation indexes were intro duced as the theoretical reference data for slab quality level evaluation. Meanwhile, both the quality loss factors relat ed to casting metallurgical rules and the adjusting factors related to casting events were taken into full consideration, which was integrated organically with theoretical analysis and expert system. The system can be widely used as an important theoretical tool for prediction and control of slab quality in slab continuous casting process.