碱性耐火材料的脱硫作用

在不同CaO含量的碱性耐火材料坩埚中加入不同硫含量的铁粉 ,于 16 0 0℃保温不同时间 ,然后分析金属中残余硫含量。结果表明 :碱性耐火材料 ,特别是CaO有脱硫作用 ,2 0 %的CaO即可取得明显的脱硫效果 ;保温时间超过 30min后 ,出现“回硫”现象 ;熔融金属中原始硫含量对脱硫率有一定的影响     

碱性耐火材料脱磷作用的研究

在石墨坩埚内,衬一层厚约10mm的不同碱性内衬,加入100g左右不同磷含量的还原铁粉,经1600℃,30min熔炼并对冷却后试样进行化学、扫描电镜和能谱分析。发现耐火材料中含有25％CaO时可使金属中的磷含量大幅度下降,而进一步提高CaO含量可在一定程度上提高其脱磷率,但提高的幅度有限。熔融金属中原始磷含量也影响CaO的脱磷率,但原始磷含量达到0.1％时,其影响已很小。并对脱磷机理做了说明。     

Service of basic refractories with additions of fused aluminomagnesia spinel in open hearth roofs

Conclusions We developed the basic technical parameters for making high-quality roof refractories, using electrofused spinel.Tests carried out in the roofs of large tonnage open-hearth furnaces, working with the use of oxygen, showed that the wear resistance of these refractories is 30% greater than that of ordinary periclase-spinel.Refractories containing 30% nonchromite spinel should be considered as the most promising.It would be desirable to produce and test large batches of these refractories in service.Translated from Ogneupory, No. 5, pp. 22–27, May, 1968.     

Service of refractories in a blast furnace shaft

Conclusions The destruction of the refractory structure of a blast furnace depends on the properties of the refractory, the system of cooling the lining, the furnace operating cycle, the action of alkalis, primary slags, zincite, and sooty carbon, the running of the furnace, the thermal stresses in the structure, abrasion of the batch, and other factors.To increase the life of the shaft lining in a blast furnace it is necessary to use dense, high-fired brick for the structure, prepared on the basis of high-grade kaolin raw materials with the minimum content of fluxing oxides; to use the best system of cooling the shaft; and to stabilize the blast furnace working cycle, especially during the first period of operation after the blow right up to complete drying-out of the refractory structure.Translated from Ogneupory, No. 7, pp. 28–37, July, 1968.     

Service of refractories in a double-bath steel melting furnace

Conclusions In the double-bath steel melting furnace blowing the bath with oxygen is done with a greater intensity than in open hearth furnaces. However, the working cycle and the design parameters of the double-bath furnace permit substantially lower specific labor and material expenditure on repairs than for open hearth furnaces. The specific consumption of roof refractories for the double-bath furnace is much less than for the open hearth, and work is being done to reduce it even further.B. I. Falkon and V. M. Saldeep took part in this work.Translated from Ogneupory, No. 1, pp. 27–30, January, 1973.     

碱性耐火材料在白银炼铜炉上的使用

简述了炼钢炉的原理及特点，镁铝、镁络耐火材料的性能及其在炼铜炉上的使用。初探了炼钢炉渣线部位用普通镁铝砖、半再结合镁铬砖的损毁机理，结果表明：半再结合镁络砖的抗侵蚀性明显优于普通镁铝砖。     

Synthesis and characterization of reaction-bonded calcium alumino-titanate-bauxite-SiC composite refractories in a reducing atmosphere

To take full advantage of the excellent properties of CA₆ present in calcium alumino-titanate (CAT) and reduce the formation of the low melting point phase (anorthite), CAT-bauxite-SiC composite refractories were fabricated under buried sintering in order to achieve low thermal expansion, superior high-temperature performance, and increased alkali resistance. Furthermore, the corrosion mechanism of K vapor was investigated by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results show that CA₆ present in CAT can be partially retained and the hot strength of CAT-bauxite-SiC composites slowly decreases when the amount of CAT added is less than 21.6?wt%. The cold strength and bulk density decrease with the CAT content, and the residual ratio of MOR firstly decreases and subsequently increases with the CAT content. For the specimens with CAT additions, 43.2?wt% CAT results in the highest volume expansion at high temperatures. It is proposed that the corrosion mechanism of CAT aggregates under buried sintering is as follows: 1) K vapors penetrate into the CAT with high CA₆ content through the lamellar CA₆ gap and deposit on the inner regions of CAT; and 2) K vapors react with corundum and anorthite present in CAT and cause the microstructural destruction of CAT due to a decrease in the amount of the Al₂O₃-CaO-SiO₂ liquid phase in the CAT. The alkali resistance of the CAT-bauxite-SiC composites decreases as the CAT content increases, which is attributed to poor sintering densification and high apparent porosity.     

Service tests of chrome-spinel-periclase refractories

Conclusions In chemical composition the experimental chrome-spinel-periclase refractories are characterized by a high degree of purity. The total content of impurity oxides of silicon, calcium, and iron does not exceed 2%. The parts possess increased density, porosity, and slag resistance but a lower heat resistance than the imported refractories with a silica content of 0.5%.Comparative tests of the experimental chrome-spinel-periclase parts (area of about 0.5 m²) and the imported refractories with a silica content of 0.5% in the slag belt of an ASEA-SKF installation ladle showed similar lives of them. For a final experimental test it would be desirable to produce a larger experimental production lot of the chrome-spinel-periclase refractories and to test them in the slag zone of ASEA-SKF ladles.Translated from Ogneupory, No. 1, pp. 44–47, January, 1985.     

Service of refractories in a double bath steel melting furnace

Conclusions The absence of regenerators, the small quantity of easily removable powdery slag in the slaggers, the low wear of the head structure, the verticals, and the lower structure of the furnace substantially simplify repair operations.The much simpler construction of the furnace, compared with that of an open-hearth furnace, enables us to eliminate cumbersome switching systems; the entire switching system consists of two gate valves. The design of the furnace guarantees the use of industrial repair methods.The specific consumption of refractories and fuel for a double bath furnace are less than for the openhearth furnace, but the oxygen consumption is higher, and the output of acceptable metal less.Translated from Ogneupory, No.6, pp. 25–29, June, 1968.     

Experiments with flame guncreting of basic refractories

Conclusions A laboratory installation for flame guncreting was designed, built, and tested. A method was developed for flame guncreting of basic refractories. The guncreted layer obtained as a result of flame guncreting is formally bonded with the refractory, and in its density and structure, is significantly better than it.Translated from Ogneupory, No.2, pp.54–57, February, 1967.     

Slag and hot-slag resistance of basic refractories

Conclusions Using the instrument described, which has been improved in design for testing refractory materials for slag and hot slag resistance, we investigated the properties of magnesite, magnesite-chromite, and chrome-magnesite specimens. It was established that their life is determined by the resistance of the refractory bond. The best resistance is possessed by periclase-spinel specimens. An increase in the content of calcium oxide in the slags reduces the slag resistance of all periclase-spinel refractories that were tested. Impregnating the magnesite products with a saturated solution of chromium acetate and firing them after impregnation at 400–500°C markedly increases their slag resistance.Translated from Ogneupory, No. 7, pp. 47–52, July, 1968.