Development of usage rates of pericilase — Chromite refractories for open-hearth and twin-bath furnace roof repairs

Based on the data of a detailed investigation with the use of multi-factor correlation and regression analyses, a complex of multi-factor models has been studied and constructed for the development of absolute usage rates of periclase-chromite refractories in ongoing repairs of the lining of the main roof and port roofs of open-hearth and twin-bath furnaces with capacities ranging from 200 to 900 tons. Calculations by the models demonstrated a sufficiently high accuracy of prediction.Translated from Ogneupory, No. 2, pp. 28 – 31, February, 1994.     

Use of new ceramic and refractory materials — an important factor in improving the economic and energy efficiency of enterprises,and their ecological security

In productions costs of enterprises the proportion expended in energy resources often becomes predominant, and therefore the competitiveness of a product from domestic enterprises depends considerably on rational consumption of energy resources. One main areas for resolving the problem of economic and energy efficiency and the ecological cleanliness of enterprises in the industrial and social sphere should be the creation of fundamentally new materials, organization of the production of a variety of components based on these materials, and also different devices based upon them, and application of these components and devices instead of obsolescent examples used traditionally.     

Compressive creep testing of refractories at elevated loads—Device,material law and evaluation techniques

In order to cost-effectively characterize the high temperature compressive creep behaviour of refractories a testing device was designed for application at elevated loads. Special measures have been taken necessary to enable an even stress distribution within the specimen. To identify Norton-Bailey strain hardening creep law parameters a general inverse procedure using a Levenberg–Marquardt algorithm was developed. Satisfying experimental results could be received from the creep measurement in a wide range of temperatures and loads for both shaped and unshaped materials. By fitting the strain/time curves the creep law parameters of refractories under various temperatures can be precisely identified. The measurements also reveal that at elevated loads all three creep stages can be observed.     

Ultrasonic measurement of Young’s modulus MgO/C refractories at high temperature

The paper deals with the elastic behavior of MgO/C refractories used in BOF at temperatures up to 1400°C in air or inert atmosphere. Measurements have been made by the way of a high temperature ultrasonic technique. Heating-cooling cycles and long time aging in the range 700–1400°C show strong variations of Young’s modulus which have been interpreted with the aid of XRD analysis, SEM observations and EDS analysis. Carbon oxidation and sintering of MgO particles are found to be responsible of the major parts of the measured evolutions. ©     

Effect of nanocarbon sources on microstructure and mechanical properties of MgO–C refractories

A study of microstructural evolution, mechanical and thermo-mechanical properties of MgO–C refractories, based on graphite oxide nanosheets (GONs), carbon nanotubes (CNTs) and carbon black (CB), was carried out by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDS), three-point bending and thermal shock tests. Meanwhile, these results were compared to the conventional MgO–C refractory containing 10 wt% flaky graphite prepared under the same conditions. The results showed that higher cold modulus of rupture was obtained for the composition containing GONs, and the composition containing CNTs exhibited larger displacement after coking at 1000 °C and 1400 °C. Also, the addition of nanocarbons led to an improvement of the thermal shock resistance; in particular, both compositions containing CNTs and CB had higher residual strength ratio, approaching the thermal shock resistance of the reference composition containing 10 wt% flaky graphite, as it was associated with the presence of nanocarbons and in-situ formation of ceramic phases in the matrix.     

Market Status and Development of Cannabis Aativa Cosmetics in the Times of “Secondary-Constituent Community”

Since 2020,with the advent of the COVID-19 epidemic,the upsurge of the concept of“Constituent community”in the cosmetics industry has gradually subsided.The phenomenon of only focuing on the components but not on the synergies of the product system has gradually ebbed.On the other hand,with the popularity of the concept of industrial Cannabis sativa and Cannabis sativa cosmetics both at home and abroad,the Cannabis sativa cosmetics that replace the single effect propaganda of the Constituent community have been increasingly recognized by consumers,and industrial Cannabis sativa is increasingly widely used in cosmetics.For the development of Cannabis sativa cosmetics in the times of“Secondary-Constituent community”,the market status of Cannabis sativa cosmetics in China and abroad was analyzed in this paper.At the same time,the future development prospect of domestic Cannabis sativa cosmetics was preliminarily estimated and prospected,which was helpful for the development of Cannabis sativa cosmetics and provided the evaluation basis for the investment and development of domestic Cannabis sativa cosmetics.     

Thermal shock resistance of magnesia–chrome refractories—experimental and criterial evaluation

Eleven commercially available magnesia–chrome refractories have been tested. Their basic properties have been determined along with bending strengths at 20,950 and 1400 °C, linear thermal expansion coefficients at 950 °C and 1400 °C, Young's modulus by the static method and the work of fracture at 950 °C. Young's modulus was determined within the temperature range 20–1000 °C, in the process of heating and cooling. The values of thermal shock resistance R_st and R₄ were calculated and correlated to thermal shock resistance (TSR). It has been demonstrated that the R_st criterion is a useful tool to forecast TSR, no matter whether the value of the E modulus is determined by the static or dynamic method. The values of Young's modulus obtained by various methods at 20 °C and 950 °C have been compared. It has been proven that Young's modulus dependence on temperature is a specific feature of a given material.     

87 companies have been closed or moved and 18 enterprises have obtained the ＂cleaner production enterprise certification of Guangdong Province＂

On October 31,2009 ＂Boshan Cup＂ China Ceramic and Colored Glaze Art Prize-Giving Competition, which is praised as ＂Ceramics and Colored Glaze National Games＂, was held in Shandong Province, where the Eleventh National Games had just completed. In the competition, Master Huo Ran, who won the highest prize among the works of Guangdong Province participating in the competition, was invited by the organizing committee as the prize receiving guest and as a representative of Guangdong Province to participate in the award ceremony and other series of activities held in Boshan. Shandong Province.     

Hydrogen production via sorption enhanced reforming of methane: Development of a novel hybrid material—reforming catalyst and CO2 sorbent

This study presents the development and the evaluation of a new hybrid material, NiO–CaO–Ca₁₂Al₁₄O₃₃, which functions simultaneously as reforming catalyst and CO₂ sorbent for application in sorption enhanced reforming. CaO–Ca₁₂Al₁₄O₃₃ acts as an effective CO₂ sorbent and also as a support for the active metallic Ni particles. This idea aims to overcome the complex problems related with handling of the two different solids (catalyst and CO₂ sorbent) required for sorption enhanced reforming and also to increase the industrial potential of the process by decreasing the cost of the total solid material used. The CO₂ fixation ability of the new material (56% carbonation conversion) remains unchanged for 45 cycles of sorption-desorption. It is assumed that the presence of NiO acts synergetically with Ca₁₂Al₁₄O₃₃ to the excellent stability of the novel material compared with other CaO-based sorbents. The effect of NiO loading on the catalytic functionality of the material, under methane sorption enhanced reforming conditions was studied and the results showed that conversion goes through a maximum (80%) in the presence of the hybrid material with 16 wt% Ni loading. The hybrid material with the optimum metallic loading was tested at 650 °C and methane to steam ratio equal to 3.4. The presence of free CaO resulted in the capture of CO₂ formed, producing a stream rich in H₂ (90%) and poor in CO₂ (2.8%) and CO (2%).     

Development of an integrated process for the production of high-purity γ-aminobutyric acid from fermentation broth

γ-Aminobutyric acid (GABA), a natural non-protein amino acid, plays an irreplaceable role in regulating the life activities of organisms. Nowadays, the separation and purification of food-grade GABA from fermentation broth is still a great challenge. This research utilized monosodium glutamate as a substrate for the production of high-purity GABA via an integrated process incorporating fermentation, purification, and crystallization. Firstly, 147 g·L^-1 GABA with a yield of 99.8% was achieved through fed-batch fermentation by Lactobacillus brevis CE701. Secondly, three integrated purification methods by ethanol precipitation were compared, and crude GABA with a purity of 89.85% was obtained by the optimized method. Thirdly, GABA crystals with a purity of 98.69% and a yield of 60% were further obtained through a designed crystallization process. Furthermore, the GABA industrial production process model was established by Superproper Designer V10 software, and material balance and economic analysis were carried out. Ethanol used in the process was recovered with a recovery of 98.79% through Aspen simulated extractive distillation. Then the fixed investment (equipment purchase and installation costs) for an annual production of 80 t GABA will be about 833000 USD; the total annual production cost (raw material cost and utility cost) will be about 641000 USD. The annual sale of GABA may be at the range of 2400000-4000000 USD and the payback period will be about 1-2 year. This integrated process provides a potential way for the industrial-scale production of food-grade GABA.     

Analysis on microcrystalline graphite and properties of MgO–C refractories with microcrystalline graphite

The composition and microstructure of microcrystalline graphite were studied by X-ray diffraction, differential thermal analysis–thermogravimetry, SEM and energy dispersive analysis in this paper. The chemical composition of ash in microcrystalline graphite was also analysed in the study. The microcrystalline graphite was introduced in MgO–C refractories fabrication to investigate the influence of microcrystalline graphite on the main properties of MgO–C refractories. The oxidation resistance, thermal shock resistance, hot bending strength and expansion rate of MgO–C samples with microcrystalline graphite and flake graphite were investigated in this study. It is indicated that the proper addition amount of microcrystalline graphite in MgO–C refractories should be no more than 4?wt-%.