Chemical elements
    Physical Properties
    Chemical Properties
      Zinc Fluoride
      Zinc Chloride
      Zinc Oxychlorides
      Zinc Bromide
      Zinc Iodide
      Zinc Hypochlorite
      Zinc Perchlorate
      Zinc Bromate
      Zinc Iodate
      Zinc Periodate
      Zinc Oxide
      Zinc Hydroxide
      Zinc Peroxide
      Zinc Sulphide
      Zinc Hydrosulphite
      Zinc Thiosulphate
      Zinc Sulphite
      Zinc Sulphate
      Zinc Dithionate
      Zinc Tetrathionate
      Zinc Pentathionate
      Zinc Selenide
      Zinc Selenites
      Zinc Selenate
      Zinc Telluride
      Zinc Tellurate
      Zinc Chromite
      Zinc Chromate
      Zinc Dichromate
      Zinc Molybdate
      Zinc Tungstate
      Zinc Nitride
      Zinc Azide
      Zinc Amide
      Zinc Ammoniate
      Zinc Nitrite
      Zinc Nitrate
      Basic Zinc Nitrates
      Zinc Phosphide
      Zinc Hydrophosphide
      Zinc Hypophosphite
      Zinc Phosphite
      Zinc Thiophosphite
      Zinc Orthophosphate
      Zinc Pyrophosphate
      Ammonium Zinc Orthophosphate
      Zinc Thiophosphates
      Zinc Arsenide
      Zinc Arsenite
      Zinc Arsenates
      Zinc Metantimonate
      Thioantimony Salts of Zinc
      Zinc Carbonate
      Zinc Thiocarbonate
      Zinc Cyanide
      Zinc Thiocyanate
      Zinc Silicide
      Zinc Silicates
      Zinc Borates
      Zinc Perborate
    PDB 12ca-1ai0
    PDB 1aiy-1b6z
    PDB 1b71-1bs8
    PDB 1bsk-1cao
    PDB 1caq-1ctt
    PDB 1ctu-1de6
    PDB 1def-1dy0
    PDB 1dy1-1ed6
    PDB 1ed8-1exk
    PDB 1eyf-1fj9
    PDB 1fjg-1g0e
    PDB 1g0f-1gkq
    PDB 1gkr-1ha5
    PDB 1hbm-1hso
    PDB 1hsz-1i6v
    PDB 1i73-1im5
    PDB 1iml-1jcv
    PDB 1jcz-1jy8
    PDB 1jyb-1kh4
    PDB 1kh5-1kys
    PDB 1kzo-1llm
    PDB 1llu-1m7j
    PDB 1m9j-1mwo
    PDB 1mwq-1ndv
    PDB 1ndw-1nyq
    PDB 1nyr-1os4
    PDB 1os9-1p9w
    PDB 1paa-1pud
    PDB 1pv8-1q9l
    PDB 1q9m-1qv6
    PDB 1qv7-1r6o
    PDB 1r79-1ro9
    PDB 1ror-1sfo
    PDB 1sg0-1t3k
    PDB 1t4k-1tkh
    PDB 1tkj-1u0l
    PDB 1u10-1ums
    PDB 1umt-1v67
    PDB 1v6g-1vrq
    PDB 1vs0-1wew
    PDB 1wfe-1wwf
    PDB 1wwg-1xb1
    PDB 1xb8-1xpz
    PDB 1xq0-1y5w
    PDB 1y5x-1ylk
    PDB 1ylo-1z8r
    PDB 1z93-1zkx
    PDB 1zl6-258l
    PDB 2a03-2afo
    PDB 2afs-2atq
    PDB 2au3-2bfz
    PDB 2bg2-2c3a
    PDB 2c4r-2cij
    PDB 2cim-2czr
    PDB 2d0w-2djw
    PDB 2dkc-2e1b
    PDB 2e1s-2eer
    PDB 2eex-2em4
    PDB 2em5-2eoj
    PDB 2eok-2erq
    PDB 2esf-2fa7
    PDB 2fac-2fpx
    PDB 2fqp-2g84
    PDB 2g87-2gvf
    PDB 2gvi-2han
    PDB 2hap-2huc
    PDB 2hue-2imc
    PDB 2imr-2j65
    PDB 2j6a-2jq5
    PDB 2jr7-2kfn
    PDB 2kft-2l75
    PDB 2lgv-2nx9
    PDB 2nxa-2oc8
    PDB 2occ-2osm
    PDB 2oso-2p53
    PDB 2p57-2pow
    PDB 2ppb-2q8j
    PDB 2qa1-2qp6
    PDB 2qpj-2r71
    PDB 2r74-2sod
    PDB 2srt-2v86
    PDB 2v87-2vp7
    PDB 2vpb-2vyo
    PDB 2vz5-2wey
    PDB 2wfq-2wx0
    PDB 2wx1-2xam
    PDB 2xan-2xr9
    PDB 2xrg-2ytd
    PDB 2yte-2z30
    PDB 2z3g-2zet
    PDB 2zh0-3a32
    PDB 3a36-3aoi
    PDB 3at1-3bk1
    PDB 3bk2-3byr
    PDB 3byw-3cia
    PDB 3ciz-3d08
    PDB 3d09-3dbu
    PDB 3dc3-3dp6
    PDB 3dpe-3e1w
    PDB 3e1z-3ebh
    PDB 3ebi-3epk
    PDB 3epl-3f28
    PDB 3f2b-3fhe
    PDB 3fhp-3ful
    PDB 3fum-3g9y
    PDB 3ga3-3gpu
    PDB 3gpx-3h2w
    PDB 3h3e-3hfy
    PDB 3hgz-3hsn
    PDB 3hso-3i8v
    PDB 3i9b-3ij6
    PDB 3ijf-3ixe
    PDB 3iz0-3k34
    PDB 3k35-3kiy
    PDB 3kj1-3kvt
    PDB 3kwa-3lat
    PDB 3lcn-3lrr
    PDB 3ls1-3m1n
    PDB 3m1v-3mek
    PDB 3men-3mru
    PDB 3ms0-3n63
    PDB 3n64-3nin
    PDB 3nis-3ny2
    PDB 3ny3-3ohc
    PDB 3ohd-3oyl
    PDB 3oym-3pih
    PDB 3pki-3r0d
    PDB 3rj7-3t74
    PDB 3t87-3u9g
    PDB 3ua7-3v24
    PDB 3v25-4agl
    PDB 4agm-4dih
    PDB 4dii-4efs
    PDB 4eg2-4fc8
    PDB 4fgm-6tli
    PDB 6tmn-9nse

Zinc Sulphide, ZnS

Zinc Sulphide, ZnS, occurs naturally as the valuable ores wurtzite and zinc blende. Zinc blende (sphalerite) crystallises in the tetrahedral group of the isometric system, with a hardness of 3.5-4 and a density of 4.05. Wurtzite crystallises in the hemimorphic group of the hexagonal system, with a hardness of 3.54 and a density of 3.98. Both minerals vary in colour from dark brown to black - blende being often black like coal.

Crystalline zinc sulphide is prepared most directly by subliming the amorphous form in an electric furnace. Since the crystals of zinc sulphide obtained by sublimation are hexagonal, wurtzite apparently represents the more stable form at high temperatures. The transformation temperature of blende into wurtzite apparently varies with the associated impurities. The reverse change, when the temperature falls, is slow, and may occupy two or three days. The sublimation of zinc sulphide, amorphous or crystalline, has been performed in the presence of alumina, and in an atmosphere of hydrogen, nitrogen, sulphur dioxide, or hydrogen sulphide.

Other methods of obtaining crystalline zinc sulphide (wurtzite) are -

  1. Heating zinc oxide or silicate in sulphur vapour at a red heat.
  2. Interaction between zinc vapour and hydrogen sulphide.
  3. Melting together zinc sulphate, barium sulphide, and calcium fluoride.
  4. Action of zinc chloride vapour, diluted with carbon dioxide, on some metallic sulphides, especially tin sulphide.

Crystals of blende are said to be obtained by heating zinc sulphide in a solution of hydrogen sulphide under pressure, by subjecting zinc chloride vapour to the action of hydrogen sulphide, and by the action of carbon disulphide on zinc oxide at a white heat.

White amorphous zinc sulphide is precipitated by passing hydrogen sulphide through solutions of zinc salts. Since it is less soluble than the oxide or carbonate, suspensions of these in water are converted into sulphide by hydrogen sulphide. Zinc sulphide is perceptibly soluble in sodium hydrogen sulphide, freely in mineral acids, and somewhat soluble in ammonium chloride on boiling.

The precipitation of zinc sulphide by passing hydrogen sulphide through solutions of its salts is not usually quantitative: this is usually explained by the reversibility of the reaction

According to Glixelli, the reaction
ZnSO4+H2S = ZnS+SO4

is not reversible, partial precipitation arising from false equilibria, and prolonged passage of hydrogen sulphide, at ordinary temperature, through ¼ and ½ molar solutions of zinc sulphate, precipitates the zinc completely.

When zinc sulphide is precipitated in media in which it is slightly soluble, as in the presence of weak acids, it is either crystalline or becomes so on standing. According to Villiers, it is soluble in sodium hydrogen sulphide at the moment of precipitation, and passes from this etat protomorphique into a crystalline insoluble form with a rapidity which varies with conditions. According to Glixelli, the β-sulphide precipitated from alkaline solutions is forty-six times as soluble as the a-sulphide precipitated from acid solutions.

When zinc sulphide is first precipitated in media in which it is very insoluble it readily goes into colloidal solution. A colloidal solution has been prepared by precipitation with hydrogen sulphide in ammoniacal or neutral solution and washing with hydrogen sulphide water, and by passing hydrogen sulphide into an aqueous suspension of zinc oxide. The addition of glycerine, or other substances increasing the viscosity of the solution, facilitates the formation of these colloidal solutions, which are milky by reflected and orange by transmitted light.

Seligmann obtains a readily filterable zinc sulphide by heating a strongly ammoniacal solution, containing 0.5 grm. zinc in 200 c.c., to 60° or 80° C. and adding a slight excess of ammonium sulphide.

Zinc sulphide is tinged light brown or grey by exposure to light or heating to 60°-70° C. This behaviour, which may be due to polymerisation, is promoted by various substances and inhibited by others, and is important for the use of zinc sulphide as a pigment, whether alone or, mixed with finely divided barium sulphate, in lithophone.

The ordinary sulphide, natural or artificial, phosphoresces after exposure to light. This phosphorescence is affected by traces of other metals, but the data seem to be somewhat contradictory. A similar phosphorescence is also stimulated by exposing the sulphide to the action of ozone. Apparently there is no phosphorescence in ordinary precipitated zinc sulphide, but if it is heated for about one and a half hours at 650°-900° C. it will phosphoresce under light, Becquerel rays, X-rays, cathode rays, and radioactive emanations. The favouring conditions for phosphorescent behaviour seem to be semi-crystalline condition and the presence of chlorine ions. The latter may strain the particles of zinc sulphide by coating them with zinc chloride. The luminescence of crystalline zinc sulphide under X-rays is increased by the presence of 1.30 per cent, of cadmium sulphide in solid solution.

The reaction
ZnS+H2O = H2S+ZnO

begins at a dull red heat and is rapid at higher temperatures.

Oxygen converts zinc sulphide into sulphate at 500° C., and the sulphate decomposes into oxide at higher temperatures. Carbon reduces zinc sulphide to metal at a high temperature - carbon disulphide being formed.

The specific heat of zinc blende is about 0.12. According to Regnault, the specific heat of zinc sulphide is 0.12303.

[Zn] + [S] = [ZnS]+43.0 Cal.
[Zn] + [S(rhombic)] = [ZnS(cryst)]+41.3 Cal.
The reaction
ZnS+3CO2 = ZnO + SO2+3CO

begins at 750° C. and is vigorous at 1000° C.

There are probably no definite hydrates of zinc sulphide, though some have been reported.

A white pentasulphide, ZnS5, is said to be precipitated from solutions of zinc salts by potassium pentasulphide, which is decomposed by acids with the evolution of hydrogen sulphide and deposition of sulphur.

An unstable zinc hydrogen sulphide, Zn(HS)2, may be produced during the action of hydrogen sulphide or sodium hydrogen sulphide on solutions of zinc salts.

The oxysulphide, 4ZnS.ZnO, occurs naturally as voltzite in globular masses with a hardness of 3-3.5 and a density of 4.9-5.0.

The double sulphides, Na2S.3ZnS, K2S.3ZnS, Ag2S.3ZnS, and CuS.3ZnS, have been described.

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