The hydration of cement containing accelerating agent based on calcium aluminate with different molar ratio of CaO/Al₂O₃ and crystallinity was investigated to clarify relationship between quick setting property and hydration characteristics of calcium aluminate. The results obtained are summarized as follows.
(1) Heat of dissolution of none crystalline calcium aluminate is about 5% larger than that of crystalline calcium aluminate in spite of varying molar ratio of CaO/Al₂O₃. Also, concentration of Ca²⁺ and Al³⁺ in the solution of calcium aluminate within 3 min. after mixing with water depends largely on CaO/Al₂O₃ molar ratio of it. The larger the molar ratio of CaO/Al₂O₃, the less concentration.
Heat evolution amount in the hydration of calcium aluminate alone within one hour after mixing with water is influenced largely by molar ratio of CaO/Al₂O₃. With increase of CaO/Al₂O₃ molar ratio, the heat evolution amount becomes larger.
(2) Cement containing 7% accelerating agent which consists of calcium aluminate, NaAlO₂, Al (OH) ₃, CaO, Na2CO₃, and CaSO₄ brings quick setting in 30 sec. after JIS method. Not only none crystalline calcium aluminate but also crystalline calcium aluminate with high CaO/Al₂O₃ molar ratio, C₃A, are more suitable for this case.
Heat evolution amont of cement containing accelerating agent in initial stage depends on quick setting property. However, this trend is different from that of calcium aluminate alone.
(3) Quick setting property corresponds well with the amount of ettringite formed in cement paste. A little ettringite forms in cement paste with accelerating agent based on crystalline calcium aluminate with low CaO/Al₂O₃ molar ratio, C₁₂A₇. This is different from that of none crystalline calcium aluminate and crystalline calcium aluminate with high CaO/Al₂O₃ molar ratio, C3A which form much ettringite.
Main hydrate is ettringite in initial hydration of cement containing accelerating agent. It's size is about 5 to 10, um in length, which is much larger than that in usual cement paste and connects with cement particles each other. This hydration texture brings quick setting property.

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Calcium ferrite monochloride hydrate (CFMH) was prepared by reaction between Ca (OH_{) 2} and FeCl₃ in aqueous solution under the atmospheric pressure at 60°C. CFMH obtained was studied by means of X-ray diffraction (XRD), electron diffraction (ED), scanning electron microscope-energy dispersive X-ray analyser (SEM-EDX) and thermogravimetry-differential thermal analysis (TG-DTA). Microscopic examination of CFMH showed a thin plate-like pseudohexagonal crystallite : maximum diameter ca. 1 pm; thickness ca. 0.1 pm, and a single crystal pattern of sharp hexagonal reciprocal lattice with a₀=0.59 nm. From SEM-EDX study of these hexagonal plates, [Ca_1.8Fe_1.2 (OH) ₆] (Cl_1.0, OH_0.2) ·1.7 H₂O was given to their average composition per formula. Assuming ED pattern of CFMH to be hexagonal, the lattice constants a₀=0.59 nm and c₀ =2.33 nm were determined usung (00l) and (110) reflections. From TG-DTA, XRD and SEM-EDS studies, the following was confirmed : interlayerwater molecule of CFMH was continuously lost with the increase of temperature in the temperature range from room temperature to 110°C, and water being contained in interlayer per formula of CFMH at 110°C was only one molcule; all of residual interlayer water molcule was discontinuously lost at 120°C and any water molcule as well as any hydroxide ion were not existent in interlayer in the temperature range from 120°C to 250°C; CFMH calcined at 400°C was amorphous : an unknown pseudoorthorhombic chloride containing compound analogous to crystal structure of Ca₂Fe₂O₅ appeared in the temperature range from 600°C to 1000°C and this compound was decomposed releasing chlorine gas above 1000°C and finlly crystallized as Ca₂Fe₂O₅ at 1400°C.

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The aluminophosphate molecular sieve VPI-5 composed of 18-membered rings was prepared under the hydrothermal conditions. Then several variants as to alumina source, ratio of reactants, aging temperature, aging duration time and organic template were tried.
(1) The reactivity of alumina sources was investigated by analyzing the amount of unreacted H₃PO₄ in the suspensions after the reaction for 1h-21d in the temperature range from room temperature to 80°C and the alumina sources were arranged as aluminum isopropoxide, pseudo-boehmite and bayerite in order of reactivity. At 60°C AlPO₄.2H₂O was also included in the solid.
(2) The optimum condition for preparing VPI-5 was at 140°C for 21h by using the precusor gel which was obtained by aging suspension with the molar ratio of Al₂O₃ (from pseudoboehmite) : P₂O₅ : DPA : H₂O=1 : 1 : 1 : 40.

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The ferrite process, one of the disposal methods for waste water containing heavy metal ions, has been applied for model waste waters containing beryllium ions. The stability of the solid solution incorporated beryllium ions in the ferrite lattice and the applicability of resultant ferrite sludge as recycled resources were examined by X-ray analysis and magnetometry. From the analysis of sludge the X-ray diffraction patterns for the ferrite, it has been found the structure of the sludge was beryllium ferrite and that the beryllium ions existed in ferrite lattice as a stable solid solution. The lattice constants measurement revealed that it was possible to remove beryllium ions from the model waste water up to a beryllium ion concentration of 40 mg/l and that the amount of beryllium ions soluble in the ferrite lattice was about 2 mg per 1g of ferrous sulfate. The saturation magnetization of the sludge was higher than the value of 60 emu/g required on application to magnetic materials.

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Thermochemical surface characteristics of various synthetic apatites, such as Ca₁₀ (PO₄) ₆ (OH) ₂, Ca₁₀ (PO₄) ₆F₂, Sr₁₀ (PO₄) ₆ (OH) ₂ and Ba₁₀ (PO₄) ₆ (OH) ₂ were probed by measuring the heats of immersion of the apatites into various solvents and by obtaining the adsorption isotherms of water and methanol.
Electrostatic field strengths of the apatites were calculated by means of a simple and elegant method using the calorimetric data and the difference of the calculated values was found to be useful as an index of surface activities of them.
Moreover, the adsorption free energies in water were obtained by analyzing the adsorption isotherms and the difference of them was also found to have same tendency as that of the index.
1. The electrostatic field strength calculated by analyzing the calorimetric data is an useful index of employing the apatites as effective catalysts or adsorbents of column chromatography.
2. The results from the experiments of the adsorption isotherms have the same tendencies as those obtained from the experiments of the heats of immersion.

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