Abstract: An isobaric mercury dilatometer for measurements of volume changes of solid specimens under a constant hydrostatic pressure either as a function of time or as a function of temperature. It includes structures for minimizing entrapment of air in the system, accurate computerized measurements in spite of the presence of some air. A two-piece stainless steel container is equipped with a horizontally situated volume-measuring stem, a filling device, an air vent and a temperature sensor. The specimen to be studied is placed in the container which is subsequently filled with mercury up to the stem. The volume changes of the specimen is reflected to the capacitance signals of an aluminum sleeve around the stem, while the temperature sensor generates temperature-related electronic signals. Both signals are received by a computer which translates them into volume and temperature data.

Abstract: An ice porosimeter for the accurate and efficient derivation of measurements concerning the porosity of a porous material, which includes a mercury dilatometer having a mercury-filled reservoir with a capillary stem extending upwardly therefrom. The porous material to be analyzed is inserted into the reservoir after it is saturated with water. The temperature of the contents of the reservoir is then varied to cause the water in the porous material to change state, either freezing the water or melting the ice. A thermistor measures the temperature in the reservoir and transmits these readings to a means for recording those measurements. Concurrently, a condenser is placed surrounding the capillary stem of the dilatometer and is connected to electrical circuitry which induces a capacitance across the condenser.

Abstract: Cryolite (Na.sub.3 AlF.sub.6) as a source of aluminum is prepared from coal fly ash by reacting the aluminum oxide (Al.sub.2 O.sub.3) in fly ash with phosphoric acid to form aluminum phosphate, which is then converted to sodium aluminate by reaction with sodium hydroxide, and the sodium aluminate is converted to cryolite by reaction with hydrofluoric acid (HF), or equivalent reagent providing H.sup.+ and F.sup.- ions. Aluminum is thereby obtained from fly ash in a preferred form (as cryolite) for use in producing metallic aluminum.

Abstract: A hydraulic cement is prepared by reacting coal fly ash with concentrated phosphoric acid, and crushing or grinding the resulting mixture to granules or a fine powder. The reacted fly ash may be heated to reduce the water of hydration before final crushing or grinding. The resulting hydraulic cement may be mixed with sand and/or gravel aggregate to prepare mortar or concrete mixes for applications similar to Portland cement, or the fly ash cement may be mixed with soils to stabilize them.

Abstract: A method of waterproofing subterranean walls which generally comprises peeling back the sod, making a perimeter trench around the wall, making a plurality of spaced apart vertical bore holes in the soil adjacent said wall, introducing a highly ionic inorganic salt solution into the bottom of said holes without contacting the side walls of said holes, and thereafter filling the bore holes and the trench with asphaltic emulsion, and finally placing the sod back over the trench.

Abstract: An apparatus for testing soils by measuring the rate of moisture loss from soil or sediment samples is disclosed, comprising a test chamber, a fan, a heater-thermostat, a chilled water humidity control device, an automatic balance scale connected to a continuous chart recorder, a shield around the balance pan, and a magnetic damper for the balance pan. The heater-thermostat maintains a constant temperature within the chamber, while the chilled water humidity control device maintains a constant relative humidity. The fan circulates air in the chamber, and the magnetic damper and shield around the balance pan allows the soil sample to be weighed without air currents causing the balance pan to vibrate. The balance scale continually weighs the sample, with the weight being recorded on the chart recorder, thus providing a record of the rate of moisture loss. A bell jar allows the testing to be done under vacuum conditions.The method of this invention comprises the steps of:1.