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Robert W. Potter

Publications and source records attributed to Robert W. Potter.

At least 19 recordsLinked to original sources
USGS2002

Solubility of NaCl and KCl in aqueous HCl from 20 to 85°C

The solubilities of NaCl and KCl in aqueous HCl solutions were determined from 20 to 85 ° C at concentrations ranging from 0 to 20 g of HCl/100 g of solution. Equations are given that describe the solubilities over the range of conditions studied. For NaCl and KCl respectively measured solubilities show an average deviation from these equations of ??0.10 and ??0.08 g/100 g of saturated solution.

Journal of Chemical and Engineering Data↗
USGS1982

An equation correlating the solubility of quartz in water from 25° to 900°C at pressures up to 10,000 bars

The solubility of quartz in water from 25° to 900°C at specific volume of the solvent ranging from about 1 to 10 and from 300° to 600°C at specific volume of the solvent ranging from about 10 to 100 is given by an empirically derived equation of the form: log m = A + B (log V ) + C (log V ) 2 where m is the molal silica concentration, V is the specific volume of pure water, and A = −4.66206 + 0.0034063 T + 2179.7 T −1 − 1.1292 × 10 6 T −2 + 1.3543 × 10 8 T −3 B = −0.0014180 T — 806.97 T −1 C = 3.9465 × 10 −4 T T is temperature in kelvins. The experimental data used in formulating the empirical relation ranged in pressure from 1 bar at 25°C to about 10,000 bars at 900°C, and the lowest pressure in the low-density steam region was about 30 bars. According to the above equation, the average difference in molality between 518 measured and calculated solubilities is −0.016 m with a standard deviation of 0.089.

Geochimica et Cosmochimica Acta↗
USGS1978

Bibliography of the available data on the solubility of silica in water substance

The following bibliography represents the currently available experimental data for the solubility of silica in water substance as a function of temperature and pressure. These references were compiled by the silica subcommittee of Working Group IV at the 1977 meeting of LAPS in Moscow. The data summarized in these references cover the temperature range of 0° to 900°C at pressures from atmospheric to 1000 mega pascals. Preliminary examination of the data suggests that a good correlation of the solubility of silica can be obtained from temperature and log specific volume of water (Fig. 1). The available solubility data (log weight percent silica) tend to lie along smooth curves at constant temperature as a function of log specific volume of water. In addition the data appear to be reasonably consistent, such that a single equation can be derived that describes the solubility of quartz from 0° to 900°C at pressures up to 1000 mega pascals.

Open-File Report↗
USGS1978

A magnesium correction for the Na-K-Ca chemical geothermometer

Graphs and equations have been devised to correct for the adverse effects of magnesium upon the Na-K-Ca geothermometer. Either the graphs or equations can be used to determine temperature corrections when given waters have Na-K-Ca calculated temperatures above 70? C and values of R less than 50, where R = {Mg/(Mg + Ca + K)} x 100 in equivalents. Waters with values of R greater than 50 probably come from relatively cool aquifers with temperatures about equal to the measured spring temperature, irrespective of much higher calculated Na-K-Ca temperatures.

Open-File Report↗
USGS1978

Solubility of highly soluble salts in aqueous media - Part 1, NaCl, KCl, CaCl 2 , Na 2 SO 4 , and K 2 SO 4 solubilities to 100°C

A modified visual method for determining the solubility of highly soluble salts in aqueous media up to 100° C is presented. The solubilities of NaCl, KCl, CaCl 2 , Na 2 SO 4 , and K 2 SO 4 were determined up to 100° C. The tabulated experimental data and the fitted equations describing the data indicate that the previous literature data for the solubility of these salts were generally high by 0.05 to 2.0 weight percent salt.

Journal of Research of the U.S. Geological Survey↗
USGS1978

Models for calculating density and vapor pressure of geothermal brines

In a model for estimating density of a brine, the density of a natural brine at a known temperature, pressure, and composition can be calculated from the densities of the component salt solutions in the complex brine. A model for estimating vapor pressure requires two direct or indirect estimates of the vapor pressure and uses a published "reference-substance principle" to extrapolate,; these data 200° to 300° above the temperature of the highest observation. The methods can be used to estimate the partial molal volume and partial molal enthalpy of H 2 O in the natural brine and the partial molal volume change and partial molal heat change for the H2O component in the vaporization process. The equations for density and vapor pressure and the derived thermochemical properties will help in designing turbines for operation with geothermal and geopressured brines, in optimizing production conditions, and in physical and chemical modeling of a geothermal reservoir.

Journal of Research of the U.S. Geological Survey↗
USGS1977

Pressure corrections for fluid-inclusion homogenization temperatures based on the volumetric properties of the system NaCl-H 2 O

A series of pressure correction diagrams for 1-, 5-, 10-, 15-, 20-, and 25-percent NaCl solutions has been generated from the volumetric data for NaCl by R. W. Potter II and D. L. Brown in 1975. The diagrams cover the temperature range from 20° to 400° C at pressures up to 200 megapascals (2000 bars). These data can be used to correct fluid-inclusion homogenization temperatures for pressures greater than the liquid-vapor pressure-temperature curve.

Journal of Research of the U.S. Geological Survey↗
USGS1977

A new method for determining the solubility of salts in aqueous solutions at elevated temperatures

A new method for measuring the solubility of simple salts in water at elevated temperatures involves heating assemblages of salt crystals plus solution vapor at a constant rate in a platinum-lined bomb. The dissolution of the last salt crystal is evidenced by a distinct discontinuity in the pressure-temperature curve. Studies of the solubilities of NaCl and of KC1 in water yielded equations expressing the solubility as functions of temperature, t in °C, at the vapor pressure of the solutions as follows: weight percent NaCl=26.218+0.0072 t +0.000106 t 2 ±0.05 weight percent NaCl weight percent KCl=27.839+0.0794 t +0.000027 t 2 ±0.10 weight percent KCl The NaCl and KC1 data were measured over the temperature range 148° to 425°C and 148° to 371°C, respectively. However, the equation for NaCl appears to be valid over the range 0° to 800°C, and the KC1 equation appears valid over the range 100° to 450°C.

Journal of Research of the U.S. Geological Survey↗