Reduction Roasting of Titaniferous Ores

2019 ◽  
Vol 391 ◽  
pp. 215-220 ◽  
Author(s):  
Andrey N. Dmitriev ◽  
R.V. Petukhov ◽  
G.Yu. Vitkina ◽  
E.A. Vyaznikova

Questions regarding the oxidizing roasting of raw iron ore materials (agglomerate and pellets) are studied. Features of the phase structure of raw iron ore materials containing titanium and vanadium are discussed. Reducibility, durability, and temperatures of the softening and melting of metallurgical raw iron ore materials are studied in vitro. Object of research – titaniferous ores with various titanium dioxide content. The behavior of agglomerate and pellets in a blast furnace are studied, as well as the influence of their physical and chemical properties on heat and mass transfer processes using a mathematical model of the blast furnace process [1].

2021 ◽  
Vol 1026 ◽  
pp. 102-108
Author(s):  
Galina Yu. Vitkina ◽  
Andrey N. Dmitriev ◽  
Roman V. Alektorov ◽  
Elena A. Vyaznikova

Questions about the oxidative roasting of iron ore raw materials (agglomerates and pellets) are studied. Features of the phase structure of the iron ore raw materials containing titan and vanadium are discussed. Reducibility, durability, and the softening and melting temperatures of metallurgical iron ore raw materials are studied in vitro. The objects of the research are titaniferous ores containing different amounts of titan dioxide. The behaviors of agglomerates and pellets in a blast furnace are studied, and the influence of their physical and chemical properties on heat and mass transfer processes are researched by means of a mathematical model. The main indices of blast furnace smelting—productivity, coke consumption, composition of top gas, cast iron, and slag—are shown. It is established that the increase in titanium dioxide content in pellets, as the amount of concentrate with increased TiO2 content increases, does not cause deterioration in the quality of iron ore raw materials being prepared for blast furnace smelting. At the same time, as the hot strength of raw materials increases, the temperature at which softening begins increases and the temperature interval of softening of materials decreases.


Author(s):  
Loredana Stabili ◽  
Roberto Schirosi ◽  
Angela Di Benedetto ◽  
Alessandro Merendino ◽  
Luciano Villanova ◽  
...  

Although mucus plays many different roles among marine invertebrates, relatively little is known about the link between biochemical structure and function. In the present study we focused on some physical and chemical properties of the polychaeteSabella spallanzanii's mucus such as viscosity, osmolarity, electrical conductivity, elemental composition, the protein and carbohydrate content, the total lipids and fatty acid composition, and polychlorinated biphenyls (PCBs) contamination. Moreover, an antimicrobial activity of the mucus was investigated. The water content ofS. spallanzaniimucus was 96.2±0.3%. By dry weight 26±1.2% was protein, 8±0.21% was carbohydrate and only 0.1% lipid, much of the remainder of the dry weight was inorganic (about 65.2%). The estimated PCBs content was <0.005 μg g−1. The mucus ofS. spallanzaniiexerted a natural lysozyme-like activity and producedin vitrothe growth inhibition ofVibrio anguillarum, Vibrio harveyi, Pseudomonas aeruginosaandCandida albicans.The findings from this study contribute to improve the limited knowledge available on the mucus composition in invertebrates and have implications for future investigations related to employment ofS. spallanzaniimucus as a source of compounds of pharmaceutical and marine technological interest.


1969 ◽  
Vol 15 (6) ◽  
pp. 501-507 ◽  
Author(s):  
M. A. Stillwell ◽  
F. A. Wood ◽  
G. M. Strunz

A growth inhibitor with the molecular formula C10H10O4Cl2 was isolated from a medium which had supported growth of a species of Cryptosporiopsis, an imperfect fungus. The compound was named cryptosporiopsin and was characterized on the basis of its physical and chemical properties. Cryptosporiopsin was active in vitro against many wood-rotting basidiomycetes as well as some phycomycetes, ascomycetes, and deuteromycetes. It was more effective than Dithane M-22 or nystatin against the in vitro spore germination of Phytophthora infestans. It was active to varying degrees against six species of bacteria. Cryptosporiopsin was compared with Orbenin and streptomycin against a penicillin-resistant strain of Staphylococcus aureus.


2014 ◽  
Vol 887-888 ◽  
pp. 939-946
Author(s):  
Guo Ping Luo ◽  
Sheng Li Wu ◽  
Xiao Long Nie ◽  
Yi Ci Wang ◽  
Yue Cong Wang

The changes of physical and chemical properties of sodium pyroxenite gangue such as decomposition and phase transformation were researched by means of differential thermal analysis and X-ray diffraction. The results show that the natural sodium pyroxenite gangue contains the main mineral of aegirite(NaFe+3Si2O6), and it contains a number of BaSO4 and Na3Ca2(SO4)3F, etc. The water of crystallization decomposes at 554.7°C. The Na3Ca2(SO4)3F decomposes into the composite sulfate and CaF2 over a wide range of temperatures. The main mineral of aegirite(NaFe+3Si2O6) reacts with CaF2 into NaF gas at 993.4°C. The sodium pyroxenite gangue is melts and releases a small amount of SiF4 gas in the range of 1193.5-1300.7°C.


2020 ◽  
pp. 088532822095089
Author(s):  
Yuanxing Zhou ◽  
Xiaochi Ma ◽  
Zhonghai Li ◽  
Bo Wang

An effective and viable hemostatic agent is important for stopping bleeding during surgery. However, it is difficult to achieve hemostasis at uneven or deep bleeding sites using a gelatin sponge. A flowable hemostatic agent has therefore been developed by processing and improving gelatin sponge, to address bleeding under these conditions. In this study, we evaluated the efficacy, safety, and physical and chemical properties of this flowable hemostatic agent in various experiments. We examined its efficacy for stopping bleeding in a rabbit model of liver abrasion in vivo, and compared its efficacy in dynamic coagulation and erythrocyte aggregation tests with gelatin sponge in vitro. We also investigated its safety in rat histocompatibility and acute systemic toxicity tests in mice in vivo, and in hemolysis tests in vitro, to determine if the flowable hemostatic agent induced any pathological reactions or adverse events. In terms of its physical and chemical properties, we analyzed the morphology and chemical bonds of the flowable hemostatic agent by optical and electron microscopy and infrared spectroscopy, and its absorbency and density. The flowable hemostatic agent resulted in a shorter mean bleeding time, less bleeding, greater likelihood of successful hemostasis, and reduced clotting time compared with gelatin sponge. The flowable agent produced some changes in physical morphology, but no pathological changes or undesirable outcomes were detected. This flowable topical hemostatic agent thus provides a safe and more effective hemostatic method than gelatin sponge, and more promising results for intraoperative hemostasis, especially on uneven or deep bleeding surfaces.


1937 ◽  
Vol 20 (4) ◽  
pp. 621-629 ◽  
Author(s):  
Henry S. Simms ◽  
Nettie P. Stillman

Digestion of adult tissue with trypsin has been shown to stimulate its initial growth in vitro. This stimulation appeared to result from the removal of an inhibitory material from the tissue due to the proteolytic action of the trypsin. This paper shows that the fluid after the digestion contains material which inhibits the initial growth of adult chicken aorta tissue. This tissue inhibitor has been obtained from chicken, dog, and sheep aortas. It is partly precipitated by an equal volume of alcohol, and is more completely precipitated by the further addition of CaCl2 (plus a little NaOH). The inhibitor is destroyed at 100°C. but usually withstands 58°C. for 20 minutes. Moderate tryptic digestion renders it soluble without destroying it. It sometimes withstands dialysis, but at other times is lost. Its physical and chemical properties, as far as we know them, coincide with those of lactenin (a bacteriostatic substance in milk). Lactenin was found to inhibit adult tissue growth; but the tissue inhibitor failed to restrain bacterial growth. This tissue inhibitor is believed to play a rôle in limiting the growth of tissue in the adult animal.


Sign in / Sign up

Export Citation Format

Share Document