Portland cement does not contain

Options

A. `CaSiO_4`
B. `CaSiO_3`
C. `Ca_3Al_2O_6`
D. `Ca_3(PO_4)_2`

Explanation

### Step-by-Step Solution:

1. **Understanding Portland Cement Composition**:
- Portland cement is primarily composed of calcium silicates and aluminates.

2. **Identifying Major Components**:
- The main components of Portland cement include:
- **Dicalcium Silicate (Ca2SiO4)**: Approximately 26% of the composition.
- **Tricalcium Silicate (Ca3SiO5)**: Approximately 51% of the composition.
- **Tricalcium Aluminate (Ca3Al2O6)**: Approximately 11% of the composition.
- Together, these three components account for about 88% of Portland cement.

3. **Listing Other Minor Components**:
- The remaining composition of Portland cement includes:
- Iron(III) oxide (Fe2O3)
- Calcium oxide (CaO)
- Magnesium oxide (MgO)
- Other oxides like Al2O3, SiO2, and SO3 make up the remaining 12%.

4. **Identifying the Excluded Component**:
- Among the listed components, **Calcium Phosphate** is not a part of Portland cement's composition.

5. **Conclusion**:
- Therefore, the answer to the question "Portland cement does not contain" is **Calcium Phosphate**.