High-quality upgraded titanium slag obtained through semi-molten reduction with the addition of Na_(2)CO_(3)is important for the fluidizing chlorination process to produce TiO_(2)pigments.The key is the effect of Na_(...High-quality upgraded titanium slag obtained through semi-molten reduction with the addition of Na_(2)CO_(3)is important for the fluidizing chlorination process to produce TiO_(2)pigments.The key is the effect of Na_(2)CO_(3)on the reduction behavior of iron.Therefore,the effects of Na_(2)CO_(3)on reduction mechanism and kinetics of iron during deep reduction of ilmenite concentrate were studied.The results indicated that the metallization ratio of the reduced sample increased with increasing temperature,time,and dose of Na_(2)CO_(3).The addition of Na_(2)CO_(3)significantly accelerated the reduction of iron in the ilmenite concentrate and promoted the growth of iron particles.However,the addition of Na_(2)CO_(3)produced sodium iron titanates;thus,the metallization ratio of the sample decreased with an increase in the temperature and time when the temperature was above 1200℃and the time was more than 30 min.When the doses of Na_(2)CO_(3)were 0,3,and 6 wt.%,the reduction of iron was controlled by the interfacial chemical reaction,both the interfacial chemical reaction and diffusion,and diffusion,respectively,and the apparent activation energies were 134.91,64.89,and 120.82 kJ/mol,respectively.展开更多
An experiment was conducted to evaluate the growth performance and cost per gain of Brahman × local crossbred bull calves receiving three diets with varying concentrate to roughage ratio （C：R） of 75：25, 65：3...An experiment was conducted to evaluate the growth performance and cost per gain of Brahman × local crossbred bull calves receiving three diets with varying concentrate to roughage ratio （C：R） of 75：25, 65：35 and 55：45 on dry matter （DM） basis. Twelve bull calves （aging 11.5 ±1.2 months and 170.8 ± 13.0 kg live weight） divided into three equal groups were fed on three diets. The diets were balanced to 14.5% crude protein （CP） level and 10.5 MJ metabolizable energy （ME） per kg DM, formulating different concentrate mixtures. German grass （Echinoclora grousgali） and paddy straw were offered at 2：1 ratio on DM basis as roughages. The results revealed that C：R ratio did not affect （P 〉 0.05） the intake of feed and nutrients, feed efficiency （7.04, 6.94 and 6.76） and average daily gain （981,958 and 976 g）. Digestibility of nutrients was not affected （P 〉 0.05） by C：R. Animals fed diet with C：R = 55：45 had the lowest feed cost （Bangladeshi Taka 136.8 BDT/kg live weight gain）, which was increased （147.5 B DT and 153.8 BDT） non-significantly （P 〉 0.05） with the increasing level of concentrate. The diet consisting of 55% concentrate mixture showed similar results with the diet consisting of 75% concentrate mixture, but was comparatively economic. Therefore, considering the growth performance and cost per kg gain of Brahman crossbred growing calves, it may be concluded that the diet consisting of 55：45 C：R may be used for economic beef production.展开更多
There was organized a 2×2 factorial type experience in which it has been aimed the influence of forage/concentrates ratio and the effect of supplementing the ratio with full fat soya by-pass （FFS） on the produc...There was organized a 2×2 factorial type experience in which it has been aimed the influence of forage/concentrates ratio and the effect of supplementing the ratio with full fat soya by-pass （FFS） on the production performance and carcass fatty acid profile of fattening lambs. 32 Tsigai lambs were divided into 4 groups and were fed with 2 different diets regarding the forage/concentrates ratio （35/65 and 65/35, on a DM basis）, containing or not 5% FFS （full fat soya treated with formaldehyde 12.5%）. Including FFS in diet and the ratios rich in concentrates determined a significant improvement in weight gain （P〈0.01）, in the degree of food recovery and in fatty acid profile from the carcass. It has been significantly increased （P〈0.01） the weight of polyunsaturated fatty acids （PUFA） from intramuscular fat （longissimus dorsi-LD and femoral biceps-FB） and the deposit fat （subcutaneous-SC and perirenal-PR） and decreased the proportion of saturated （SFA） and monounsaturated fatty acids （MUFA）. Most significant differences were recorded about PUFA from Omega-3 series （C18：3 n-3, EPA C22：3 n-3, DPA and DHA） and CLA isomers （conjugated linolenic acid： C 18：2 C9, tl I＋C 18：2 t10, C 12）. The best profile of fatty acids, considered in light of the influence on human health （high concentration of Omega 3 fatty acids and CLA and low in SFA） was established in LD, for lambs fed with diets high in concentrates and which contained FFS （HC/S）.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.U1902217 and 52104325).
文摘High-quality upgraded titanium slag obtained through semi-molten reduction with the addition of Na_(2)CO_(3)is important for the fluidizing chlorination process to produce TiO_(2)pigments.The key is the effect of Na_(2)CO_(3)on the reduction behavior of iron.Therefore,the effects of Na_(2)CO_(3)on reduction mechanism and kinetics of iron during deep reduction of ilmenite concentrate were studied.The results indicated that the metallization ratio of the reduced sample increased with increasing temperature,time,and dose of Na_(2)CO_(3).The addition of Na_(2)CO_(3)significantly accelerated the reduction of iron in the ilmenite concentrate and promoted the growth of iron particles.However,the addition of Na_(2)CO_(3)produced sodium iron titanates;thus,the metallization ratio of the sample decreased with an increase in the temperature and time when the temperature was above 1200℃and the time was more than 30 min.When the doses of Na_(2)CO_(3)were 0,3,and 6 wt.%,the reduction of iron was controlled by the interfacial chemical reaction,both the interfacial chemical reaction and diffusion,and diffusion,respectively,and the apparent activation energies were 134.91,64.89,and 120.82 kJ/mol,respectively.
文摘An experiment was conducted to evaluate the growth performance and cost per gain of Brahman × local crossbred bull calves receiving three diets with varying concentrate to roughage ratio （C：R） of 75：25, 65：35 and 55：45 on dry matter （DM） basis. Twelve bull calves （aging 11.5 ±1.2 months and 170.8 ± 13.0 kg live weight） divided into three equal groups were fed on three diets. The diets were balanced to 14.5% crude protein （CP） level and 10.5 MJ metabolizable energy （ME） per kg DM, formulating different concentrate mixtures. German grass （Echinoclora grousgali） and paddy straw were offered at 2：1 ratio on DM basis as roughages. The results revealed that C：R ratio did not affect （P 〉 0.05） the intake of feed and nutrients, feed efficiency （7.04, 6.94 and 6.76） and average daily gain （981,958 and 976 g）. Digestibility of nutrients was not affected （P 〉 0.05） by C：R. Animals fed diet with C：R = 55：45 had the lowest feed cost （Bangladeshi Taka 136.8 BDT/kg live weight gain）, which was increased （147.5 B DT and 153.8 BDT） non-significantly （P 〉 0.05） with the increasing level of concentrate. The diet consisting of 55% concentrate mixture showed similar results with the diet consisting of 75% concentrate mixture, but was comparatively economic. Therefore, considering the growth performance and cost per kg gain of Brahman crossbred growing calves, it may be concluded that the diet consisting of 55：45 C：R may be used for economic beef production.
文摘There was organized a 2×2 factorial type experience in which it has been aimed the influence of forage/concentrates ratio and the effect of supplementing the ratio with full fat soya by-pass （FFS） on the production performance and carcass fatty acid profile of fattening lambs. 32 Tsigai lambs were divided into 4 groups and were fed with 2 different diets regarding the forage/concentrates ratio （35/65 and 65/35, on a DM basis）, containing or not 5% FFS （full fat soya treated with formaldehyde 12.5%）. Including FFS in diet and the ratios rich in concentrates determined a significant improvement in weight gain （P〈0.01）, in the degree of food recovery and in fatty acid profile from the carcass. It has been significantly increased （P〈0.01） the weight of polyunsaturated fatty acids （PUFA） from intramuscular fat （longissimus dorsi-LD and femoral biceps-FB） and the deposit fat （subcutaneous-SC and perirenal-PR） and decreased the proportion of saturated （SFA） and monounsaturated fatty acids （MUFA）. Most significant differences were recorded about PUFA from Omega-3 series （C18：3 n-3, EPA C22：3 n-3, DPA and DHA） and CLA isomers （conjugated linolenic acid： C 18：2 C9, tl I＋C 18：2 t10, C 12）. The best profile of fatty acids, considered in light of the influence on human health （high concentration of Omega 3 fatty acids and CLA and low in SFA） was established in LD, for lambs fed with diets high in concentrates and which contained FFS （HC/S）.
