Factors controlling the concentrations of thirteen rare metals in sea-water

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

35

Scientific paper

The following factors controlling the concentrations of thirteen metals (Zn, Cu, Pb, Bi, Cd, Ni, Co, Hg, Ag, Cr, Mo, W, V) in sea-water were studied: 1. (1) precipitation of insoluble compounds with ions normally present in aerated sea-water, 2. (2) precipitation of sulphides locally in reducing environments, 3. (3) adsorption by ferrous sulphide, hydrated ferric oxide, hydrated manganese dioxide, apatite, clay, and organic matter. The precipitation reactions were investigated first by calculations based on solubility data, and then by experiments in which equilibrium concentrations of the metal ions were determined in sea-water in contact with their precipitates. Adsorption was measured by adding or precipitating the various adsorbents in sea-water samples containing an excess of one of the metal ions. The principal conclusions are: 1. (1) Sea-water is greatly undersaturated with respect to all thirteen metals; in other words, precipitation of compounds with the ions normally present in aerated sea-water, even under extreme conditions of temperature and pH, cannot be responsible for the observed concentrations. 2. (2) Local precipitation of sulphides is a possible control mechanism for seven of the elements (Cu, Zn, Hg, Ag, Cd, Bi, Pb), but is probably not the chief control, because the concentrations are unrelated to sulphide solubilities. 3. (3) Adsorption is a possible mechanism for all elements except V, W, Ni, Co, and Cr; if Cr is assumed to be removed by local reduction and precipitation of the hydroxide, and the other four metals by organic reactions, the existing concentrations can be fairly adequately accounted for. Adsorption processes supplemented by organic reactions also furnish a qualitative explanation for the distribution of rare metals in sedimentary rocks of marine origin. These conclusions can probably be extended to other metals in the middle of the periodic system, but not to those on either side.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Factors controlling the concentrations of thirteen rare metals in sea-water does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Factors controlling the concentrations of thirteen rare metals in sea-water, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Factors controlling the concentrations of thirteen rare metals in sea-water will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1876013

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.