Project Details:

Solubility data related to oceanic salt systems. Part I - Binary systems containing sodium, potassium, and ammonium sulfate

(previously 583/25/89)

Series: Solubility Data Series; editor-in-chief: Mark Salomon

The objective of the project is updating and evaluating the numerous data available in the literature on binary, ternary and multicomponent systems included in oceanic salt solutions in order to allow the construction of models of sea-water, brines, bitterns and natural salt solutions. A data-bank on solubility data of such systems is of major importance in the industrial activities concerning crystallization and extraction processes, in the solution of environmental problems as well as in mining of salt deposits. It is expected to compile a data-bank with all existing data of the six components marine-type system Na+-, K+-, Mg2+-, Ca2+-/Cl-, SO₄2-//H₂O

The oceanic salt system comprises the ions Na^+-, K^+-, Mg^2+-, Ca^2+-, Cl^- and SO₄^2-. Extended evaporitic deposits in Europe (Germany, Netherlands, Spain, France, Poland, Russia), Northern (Canada) and South America (Brasilia), Africa (Congo) as well as in Asia had been formed from these ions during evaporation - crystallization processes of sea waters in geological times. Geological surveying of these deposits, their exploitation in potash mining, rock salt mining, fertilizer production, usage of rock salt mines as repository for nuclear or chemical wastes, all this requires the exact knowledge of solubility equilibria in the multi-component oceanic salt system within a broad range of temperatures. At present also solution mining of magnesium chloride for magnesium metal production is performed or in the stage of planning in a number of places world (Netherlands, Congo, Thailand, Uzbekistan). In addition, evaporation and aerosol formation from oceans are important controlling factors for the worlds climate. Understanding of the details in coupling of evaporation and crystallization processes within the droplets transported into the upper atmosphere represents a crucial part for the formulation of material and energy exchange models. Climate changes from past time periods are manifested in the complex evaporitic deposition patterns, which are interpreted on the basis of the solid-liquid equilibria of the multi-component oceanic salt system.

In 1933, d'Ans published a comprehensive bibliography and compilation of primary data for solubilities of oceanic salts, and also made preliminary evaluations of these data. No comprehensive update to the bibliography or to the compilations has been made, despite their importance. While many partial models of seawater have been reported in the literature, these make use of only limited sets of data.

The goals of this part of the overall Solubility Data Series Project are:

1. To produce up-to-date compilations of data (with bibliography), constructed in the format of the IUPAC Solubility Data Series. A partially-computerized bibliographic database with associated reprints of all relevant publications is being maintained, with over 400 relevant entries. The first of this series was published some years ago as SDS Vol. 47: Alkali Metal and Ammonium Chlorides in Water and Heavy Water: Binary Systems, R. Cohen-Adad and J.W. Lorimer, eds. (1991). A scheme for systematic extension of the series to include other binary systems, then ternary systems, etc., has been devised.
2. To devise and document appropriate methods for critical evaluation of the data. These methods will include methods for describing paragenesis of systems, for example, compositions of solid and solution phases during the evaporite sequence in removal of water from sea water.

In addition to a volume on binary systems containing sodium, potassium, and ammonium sulfate, a second volume on magnesium chloride-water and calcium chloride-water and their mixtures will be prepared - see Project 2002-034-1-500

> Nov 2004 report update (pdf file - 14KB)
To be published as part of the IUPAC-NIST Solubility Data Series. in J. Phys. Chem. Ref. Data; estimated to be completed during 2005/2006.

Project abandoned - to be restructured