SDS Volume (2968)
Volume 66. Ammonium Phosphates, p None
Original Measurements
Orekhov, I. I.; Slobodkina, G. I.; Zh. Neorg. Khim. 1972, 17, 829.
Variables:
Temperature and composition at a NH3:H3PO4 ratio = 0.5
Prepared by:
Method/Apparatus/Procedure:
An isothermal method [1] was used. Phosphoric acid neutralized by $\ce{NH3}$ to the chosen ratio was placed in round 350 mL vessels and stirred. CaO was then added in small amounts until a steady turbidity appeared. Equilibrium was ascertained by repeated analysis of the liquid phase for Ca. This was done complexometrically using fluorexon as indicator [2]. Equilibrium was reached in 4-6 hrs. The composition of the solid phase was determined petrographically and by chemical analysis.
Source and Purity of Materials:
- Chemically pure $\ce{H3PO4}$ and aqueous ammonia and reagent grade $\ce{CaO}$ were used. The $\ce{CaO}$ was powdered and sifted through a 0.16 mm mesh sieve.
Estimated Errors:
Ambient temperature: No information is given.
Mass concentration (m/v) (1): No information is given.
References
1
Bergman, A. G.; Luzhnaya, N. P.; Fiziko-Khimicheskie Osnovy Izucheniya i Ispol'zovaniya Solyanykh Mestorozhdeniy Khlorid-Sul'fatnogo Tipa, Moscow, IAN USSR (1951).
2
Moyzhes, I. B.; Ershova, V. A. Eds.; Metody Analiza pri Kontrole Proizvodstva Fosfora I Fosfornoy Kisloty Leningrad, 1968.
Components:
- Ammonia, $\ce{ NH3 }$; [7664-41-7] NIST WebBook
- Phosphoric acid, $\ce{ H3PO4 }$; [7664-38-2] NIST WebBook
- Calcium oxide, $\ce{ CaO }$; [1305-78-8] NIST WebBook
- Water, $\ce{ H2O }$; [7732-18-5] NIST WebBook
Experimental Data
Part 1. Solubility in the (NH4)3PO4-H3PO4-Ca3(PO4)2-H2O system with the ratio NH3/H3PO4 = 0.5.
| $T$ (°C) | 100w1 | 100w2 | 100w3 | 100w4 | 100w5 | 100w6 | Phase (s) () |
|---|---|---|---|---|---|---|---|
| 45 | 1.33 | 1.24 | 9.88 | 87.55 | 13.6 | 83.79 | A |
| 45 | 1.62 | 1.80 | 14.77 | 81.81 | 20.40 | 76.18 | A |
| 45 | 1.84 | 2.41 | 19.64 | 76.11 | 27.12 | 68.63 | A |
| 45 | 2.10 | 3.01 | 24.56 | 70.33 | 33.91 | 60.98 | A |
| 45 | 2.32 | 3.68 | 29.35 | 64.65 | 40.53 | 53.47 | A + B |
| 45 | 2.49 | 4.21 | 34.13 | 59.17 | 47.13 | 46.17 | A + B + C |
| 45 | 2.44 | 4.79 | 39.06 | 53.71 | 53.94 | 38.83 | B + C |
| 45 | 1.91 | 5.47 | 44.22 | 48.40 | 61.06 | 31.56 | B + C |
| 45 | 1.17 | 6.06 | 49.35 | 43.42 | 68.15 | 24.62 | B + C |
| 45 | 0.50 | 6.73 | 54.72 | 38.05 | 75.56 | 17.21 | B + C |
| 60 | 0.89 | 1.26 | 9.91 | 87.96 | 13.7 | 84.19 | A |
| 60 | 1.26 | 1.82 | 14.81 | 82.11 | 20.45 | 76.47 | A |
| 60 | 1.57 | 2.41 | 19.69 | 76.33 | 27.19 | 68.83 | A |
| 60 | 1.75 | 3.03 | 24.56 | 70.66 | 33.91 | 61.31 | A |
| 60 | 2.07 | 3.62 | 29.38 | 64.93 | 40.57 | 53.74 | A + B |
| 60 | 2.30 | 4.21 | 34.20 | 59.29 | 47.23 | 46.26 | A + B |
| 60 | 2.52 | 4.79 | 37.04 | 55.65 | 51.15 | 41.54 | A + B |
| 60 | 2.39 | 5.45 | 43.92 | 48.24 | 60.65 | 31.51 | A + B + C |
| 60 | 1.61 | 6.05 | 49.19 | 43.15 | 67.92 | 24.42 | B + C |
| 60 | 0.83 | 6.71 | 54.54 | 37.92 | 75.31 | 17.15 | B + C |
| 75 | 0.68 | 1.24 | 9.93 | 88.15 | 13.7 | 84.37 | A + B |
| 75 | 0.99 | 1.82 | 14.86 | 82.33 | 20.52 | 76.67 | A + B |
| 75 | 1.24 | 2.41 | 19.75 | 76.60 | 27.27 | 69.08 | A + B |
| 75 | 1.38 | 3.03 | 24.69 | 70.90 | 34.09 | 61.50 | A + B |
| 75 | 1.81 | 3.53 | 29.45 | 65.21 | 40.67 | 53.99 | A + B |
| 75 | 2.01 | 4.22 | 34.30 | 59.47 | 47.36 | 46.41 | A + B |
| 75 | 2.07 | 4.92 | 39.17 | 53.84 | 54.09 | 38.92 | A + B |
| 75 | 2.43 | 5.44 | 43.87 | 48.26 | 60.58 | 31.55 | A + B |
| 75 | 2.09 | 6.02 | 49.68 | 42.21 | 68.60 | 23.29 | B + C |
| 75 | 1.36 | 6.67 | 54.25 | 37.72 | 74.91 | 17.06 | B + C |
| 90 | 0.55 | 1.24 | 9.94 | 88.27 | 13.7 | 84.48 | A + B |
| 90 | 0.80 | 1.83 | 14.88 | 82.49 | 20.55 | 76.82 | A + B |
| 90 | 1.04 | 2.42 | 19.77 | 76.77 | 27.30 | 69.24 | A + B |
| 90 | 1.26 | 3.04 | 24.69 | 71.01 | 34.09 | 61.61 | A + B |
| 90 | 1.45 | 3.65 | 29.56 | 65.34 | 40.82 | 54.08 | A + B |
| 90 | 1.75 | 4.23 | 34.39 | 59.63 | 47.49 | 46.53 | A + B |
| 90 | 1.87 | 4.83 | 39.17 | 54.13 | 54.09 | 39.21 | A + B |
| 90 | 2.22 | 5.46 | 44.00 | 48.32 | 60.76 | 31.56 | A + B |
| 90 | 2.40 | 6.00 | 48.83 | 42.77 | 67.43 | 24.17 | A + B |
| 90 | 1.51 | 6.67 | 54.17 | 37.65 | 74.80 | 17.02 | B + C |
(a) These values were calculated by the compiler.
(b) This is the water content of the CaO-NH3-H3PO4-H2O system.
(c) The solid phases are: A = CaHPO4; B = NH4H2PO4; C = Ca(H2PO4)2·H2O.
