Ye'elimite is the naturally occurring form of anhydrous calcium sulfoaluminate, . It gets its name from Har Ye'elim in

Israel Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...

in the Hatrurim Basin west of the Dead Sea where it was first found in nature by

Shulamit Gross Shulamit Gross (Hebrew: שולמית גרוס; lived 1 October 1923 – 19 Sep 2012) was an Israeli mineralogist and geologist who studied the Hatrurim Formation. Biography Gross was born as Shulamit Lifszyc in Grodno, Poland (today, Hrodna, B ...

, an Israeli mineralogist and geologist who studied the

Hatrurim Formation The Hatrurim Formation or ''Mottled Zone'' is a geologic formation with outcrops all around the Dead Sea Basin: in the Negev Desert in Israel, in the Judaean Desert on the West Bank, and in western Jordan. It includes late Cretaceous to Eocene age ...

.Handbook of Mineralogy
/ref>
/ref> The mineral is cubic, with 16 formula units per

unit cell In geometry, biology, mineralogy and solid state physics, a unit cell is a repeating unit formed by the vectors spanning the points of a lattice. Despite its suggestive name, the unit cell (unlike a unit vector, for example) does not necessaril ...

, and a cell dimension of 1.8392 nm, and is readily detected and quantified in mixtures by powder x-ray diffraction.

Occurrence in cement

It is alternatively called "Klein's Compound", after Alexander Klein of the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant u ...

, who experimented with sulfoaluminate cements around 1960, although it was first described in 1957 by Ragozina. Ye'elimite is most commonly encountered as a constituent of sulfoaluminate cements, in which it is manufactured on the million-tonne-per-annum scale. It also occasionally occurs adventitiously in Portland-type cements.A E Moore, ''Cement Technology'', 7 (1976) pp 85, 134 It is thus an anhydrous mineral of the cement clinker whose idealized oxide formula is also written in the

cement chemist notation Cement chemist notation (CCN) was developed to simplify the formulas cement chemists use on a daily basis. It is a shorthand way of writing the chemical formula of oxides of calcium, silicon, and various metals. Abbreviations of oxides The ma ...

(CCN). On hydration in the presence of calcium and sulfate ions, it forms the insoluble, fibrous mineral ettringite, which provides the strength in sulfoaluminate concretes, and/or monosulfoaluminate, and aluminium hydroxide. It is manufactured by heating the appropriate quantities of finely-ground alumina, calcium carbonate and

calcium sulfate Calcium sulfate (or calcium sulphate) is the inorganic compound with the formula CaSO4 and related hydrates. In the form of γ-anhydrite (the anhydrous form), it is used as a desiccant. One particular hydrate is better known as plaster of Paris ...

to between 1100 and 1300 °C, preferably in the presence of small quantities of fluxing materials, such as Fe₂O₃. On heating above 1350 °C, ye'elimite begins to decompose to

tricalcium aluminate Tricalcium aluminate Ca3Al2O6, often formulated as 3CaO·Al2O3 to highlight the proportions of the oxides from which it is made, is the most basic of the calcium aluminates. It does not occur in nature, but is an important mineral phase in Port ...

, calcium oxide, sulfur dioxide and

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as ...

References

Aluminates Aluminium minerals Calcium minerals Cement Concrete Sulfate minerals Cubic minerals Minerals in space group 214 {{sulfate-mineral-stub

Occurrence in cement

See also

References