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G.W. Morey

Publications and source records attributed to G.W. Morey.

8 recordsLinked to original sources
USGS1967

The ternary system K2SO4 MgSO4 CaSO4

Melting and subsolidus relations in the system K 2 SO 4 MgSO 4 CaSO 4 were studied using heating-cooling curves, differential thermal analysis, optics, X-ray diffraction at room and high temperatures and by quenching techniques. Previous investigators were unable to study the binary MgSO 4 CaSO 4 system and the adjacent area in the ternary system because of the decomposition of MgSO 4 and CaSO 4 at high temperatures. This problem was partly overcome by a novel sealed-tube quenching method, by hydrothermal synthesis, and by long-time heating in the solidus. As a result of this study, we found: (1) a new compound, CaSO 4 ·3MgSO 4 (m.p. 1201°C) with a field extending into the ternary system; (2) a high temperature form of MgSO 4 with a sluggishly reversible inversion. An X-ray diffraction pattern for this polymorphic form is given; (3) the inversion of β-CaSO 4 (anhydrite) to α-CaSO 4 at 1195°C, in agreement with grahmann ; (1) (4) the melting point of MgSO 4 is 1136°C and that of CaSO 4 is 1462°C (using sealed tube methods to prevent decomposition of the sulphates); (5) calcium langbeinite (K 2 SO 4 ·2CaSO 4 ) is the only compound in the K 2 SO 4 CaSO 4 binary system. This resolved discrepancies in the results of previous investigators; (6) a continuous solid solution series between congruently melting K 2 SOP 4 ·2MgSO 4 (langbeinite) and incongruently melting K 2 SO 4 ·2CaSO 4 (calcium langbeinite); (7) the liquidus in the ternary system consists of primary phase fields of K 2 SO 4 , MgSO 4 , CaSO 4 , langbeinite-calcium langbeinite solid solution, and CaSO 4 ·3MgSO 4 . The CaSO 4 field extends over a large portion of the system. Previously reported fields for the compounds (K 2 SO 4 ·MgSO 4 ·nCaSO 4 ), K 2 SO 4 ·3CaSO 4 and K 2 SO 4 ·CaSO 4 were not found; (8) a minimum in the ternary system at: 740°C, 25% MgSO 4 , 6% CaSO 4 , 69% K 2 SO 4 ; and ternary eutectics at 882°C, 49% MgSO 4 , 19% CaSO 4 , 32% K 2 SO 4 ; and 880°, 67·5% MgSO 4 , 5% CaSO 4 , 27·5% K 2 SO 4 .

Journal of Inorganic and Nuclear Chemistry↗
USGS1965

The binary system K2SO4CaSO4

The binary system K 2 SO 4 CaSO 4 was studied by means of heating-cooling curves, differential thermal analysis, high-temperature quenching technique and by means of a heating stage mounted on an X-ray diffractometer. Compositions and quench products were identified optically and by X-ray. Limited solid solution of CaSO 4 in K 2 SO 4 was found. There is a eutectic at 875°C and 34 wt. per cent CaSO 4 . Calcium langbeinite melts incongruently at 1011°C. The melting-point of CaSO 4 (1462°C) was determined by the quenching technique using sealed platinum tubes. The only intermediate crystalline phase found in the system is K 2 SO 4 ·2CaSO 4 (calcium langbeinite).

Journal of Inorganic and Nuclear Chemistry↗
USGS1964

The system K2Mg2(SO4)3 (langbeinite)-K2Ca2(SO4)3 (calcium-langbeinite)

The join between the compositions K 2 Mg 2 (SO 4 ) 3 and K 2 Ca 2 (SO 4 ) 3 was studied by means of high-temperature equilibrium quenching techniques and by means of a heating stage mounted on an X-ray diffractometer. Complete solid solution exists in the system, but at 25°C members of the solid solution series are isometric only in the composition range 0–73·5 wt. per cent K 2 Ca 2 (SO 4 ) 3 . At compositions richer in K 2 Ca 2 (SO 4 ) 3 than 73·5 wt. per cent, members of the series are optically biaxial. At higher temperatures members of the solid solution series are isometric at successively more calcium-rich compositions and pure K 2 Ca 2 (SO 4 ) 3 is isometric above about 200 ± 2°C. The system is not binary, as mixtures richer in K 2 Ca 2 (SO 4 ) 3 than 42 wt. per cent decompose with the formation of liquid and CaSO 4 .

Journal of Inorganic and Nuclear Chemistry↗
USGS1962

The solubility of quartz in water in the temperature interval from 25° to 300° C

The solubility of quartz in water was investigated by three sets of experiments at 1000 atm P H 2 O and temperatures ranging from 45° to 300°C at water pressures appropriate for the coexistence of three phases, gaseous water, liquid, and quartz, at temperatures ranging from 69° to 240°C a long term study of the dissolution of quartz grains which were continuously tumbled in water at room temperature. Saturated silica solutions in equilibrium with quartz were obtained in a few days at temperatures above 100°C. Equilibrium is shown by reproducible results for runs of different durations and by the precipitation of quartz from initially supersaturated solutions. The differential heat of solution derived from the data obtained at 1000 atm pressure is 5.38 kcal/mole. At room temperature and pressure, highly supersaturated silica solutions were obtained by continuously rotating quartz grains and water in plastic bottles at 75 rev/min. In one run the amount of silica in solution increased to a maximum value of 395 p.p.m. after 370 days. Another run reached 80 p.p.m. silica after 386 days and then dropped to 6 p.p.m. silica. It is concluded that quartz was precipitated at room temperature from this supersaturated solution and that 6 p.p.m. is essentially the true solubility of quartz at 25°C. In contrast to the runs rotated at 75 rev/min, quartz grains, and also silica glass grains, continuously rotated in water at rev/min, each contributed less than 1 p.p.m. colorimetric silica into solution after 1 year. Thus, vigorous agitation of the liquid is necessary to remove dissolved silica from the vicinity of surfaces of both quartz and glass. Two significant factors that may have contributed to the formation of supersaturated silica solutions in the runs rotated at 75 rev/min at room temperature are stresses and structural irregularities at the surfaces of the crushed quartz grains, which contributed silica into solution more readily than well crystallized quartz the very slow rate at which dissolved silica polymerizes to species appropriate to act as nuclei for quartz growth. At the termination of the runs rotated at 75 rev/min, spikelike projections were present on many of the quartz grains. These are interpreted as indicating that abrasion was not the dominant cause for the great supersaturations which were obtained.

Geochimica et Cosmochimica Acta↗