From the results of thermodynamic calculations and petrographic examination, it has been found that in an 11 m~3 blast furnace smelting Pang-Chia-Pao iron ore, rankinite always forms as the primary crystalline phase, or in parallel with dicalcium silicate. Rankinite subsequently reacts with calcium oxide to form dicalcium silicate and reacts with fayalite to form wollastonite. These reactions can be represented as follows:2(2FeO. SiO_2)+3CaO=3CaO·2SiO_2+4FeO,3CaO·2SiO_2+CaO=2(2CaO·SiO_2),3CaO·2SiO_2+2FeO·SiO_2=3(CaO·SiO_2)+2FeO.The reduction of fayalite is also discussed.

A modified diagram of theoretical requirements of carbon in ore reduction and heat supply for iron smelting has been proposed. The carbon requirements for reduction of Fe_3O_4 and that of wustite under different degrees of direct reduction of wiistite are separately considered in the proposed diagram. It is evident that the heat requirement varies with the degree of direct reduction, and is different from that conventionally adopted by some workers.The proposed diagram indicates the possibility of reducing the coke ratio to about 450 kg/ton of pig-iron, by proper preparation of raw materials, by working with a moderate driving rate under a favourable distribution of ascending gas currents across the furnace cross section to improve the gas utilization and by lowering the starting temperature of reduction of wustite.In actual practice, a surplus of reducing agents above the equilibrium is required, in order to control a proper rate of reduction; and stronger peripheral and central gas currents are required for smoother operation. Thus, the lowest possible coke ratio and the degree of direct reduction are usually higher than that theoretically required for minimum carbon supply, and can only be attained with easily reducible sinters or pellets.

The sequence of oxidation of phosphorus, carbon and other elements in molten iron bath during steelmaking were analyzed thermodynamically by means of three methods of calculation, namely: (1) calculation of the dissociation pressure P_(o_2) of oxides; (2) calculation of the [O] content in iron bath in equilibrium with the respective elements; and (3) calculation of the free energy change of the reaction of oxidation. All calculations were made with free use of activity data. The previous works of and for calculation of P_(o_2), and that of for calculation of [O] content in iron bath in equilibrium with phosphorus and carbon were reviewed, and their impropriety and errors in calculation were discussed. It has been shown that: (1) Dephosphorization is a reaction occurring between boundary layers of liquid phases, and takes place only in the presence of a molten slag of proper composition; (2) By quick formation of a highly calcareous and ferruginous slag, it is possible in the Thomas blow, preferably at comparatively low temperatures, to eliminate phosphorus simultaneously with carbon; and (3) Increase in the partial pressure of CO would depress the oxidation of carbon and facilitate the preferential oxidation of phosphorus.

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In the application of fluidization to chemical metallurgy, many processes involve the transport of heat and mass both inside a particle and between the particle and the surrounding fluid. The term, mixed specific resistance, R′(R′=Nu′=hD_p/k_s and R′=Sh′=h_DD_P/D_s for heat and mass transfer, respectively), is proposed, through which, by means of the curve shown in Figure 2, it is possible to estimate the fraction of total resistance due to transfer inside the particle, thus permitting one to ascertain whether or not a given transport process can be effectively hastened by dilute-phase technique.The effectiveness of dilute-phase technique in accelerating transport processes is primarily due to the unique characteristics of its particle-fluid dynamics. After an analysis on the fixed bed, a single particle in a fluid, and the dense—and dilute—phase fluidized systems, the present paper points out that a differentiation should be made between the local transfer coefficient and an apparent value based on the entire system. For densephase fluidization with gases, for example, the latter may be lower than the former by 2—3 orders of magnitude. This tremendous disparity is mainly caused by the back-mixing of both the particles as a group and of the fluid, as well as by the heterogeneous nonuniformity characteristic of may a particle-fluid system. Based on the present analysis, which is duly supported by experimental evidence, it is shown that dilute-phase technique can be used effectively to reduce back-mixing and to suppress the heterogeneous nature in nonuniform velocity fronts, thus raising the values of apparent transfer coefficients to the range of the local coefficients of the idealized single particle model. From the point of view of system pressure drop, too, dilute-phase fluidization represents much lower power consumption than the corresponding fixed bed or dense-phase operation.

Under high pressure and temperature pyrite is oxidized into sulfuric acid and ferric oxide in the acid solution. According to the reaction mechanism reported in the literature, the pyrite is first converted into ferrous sulfate and then is oxidized into ferric sulfate in the solution. On further reaction the ferric salt is hydrolyzed into hydroxide and then changed into ferric oxide. Kinetic studies carried out recently in our Institute indicate that the reaction product α-Fe_2O_3 is the direct oxidation product of pyrite and a new reaction mechanism was proposed. Radioactive Fe~(55,59) was used in this study as tracer to study the reaction mechanism. Results are in agreement with the mechanism proposed recently and indicate that the one reported in the literature is incorrect.

The possibility of the development of Fe-Mn-Al austenitic steels has been investigated with special attention paid to the effect of Mo, W, Ti, V, Cr or Si on the stability of austenite, their high-temperature strength and tonghness, as well as their resistance to oxidation and corrosion.It was found that two alloys have good tensile and stress-rupture properties comparable to those of high Cr-Ni bearing steels such as 257 Ti and one alloy has oxidation resisting property similar to that of 13% Cr steel. However, their corrosion resistance is rather poor and this seems to be the main objection for them to be used as high-temperature steels. Cladding and surface coating are suggested as possible remedies.Some of the alloys have low magnetic permeability and high impact values at-178℃, thus enabling them to be considered as potential non-magnetic and low-temperature steels.

Single crystals of antimony (99.8%) were very brittle at room temperature and twins occurred abundantely during deformation. Their plasticity was improved with increasing temperature and many slip lines were found at 200℃. By means of metallographyic and X-ray methods, it was found that the twinning system is {110} <100> and the slip plane is {111}.

A general review of the strengthening characteristics of the nickel-base superalloys and a primary study of principles of alloying of nickel were described. Three types of strengthening mechanisms of nickel-base alloys: solution-hardening, precipitation-hardening, and grain-boundary hardening, are discussed.