Reaction mass of Limestone and calcium fluoride and calcium sulfate

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

27 February 2017

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

The sample is added to water until there is no dissolved product then the clear solution is injected on ionic chromatography for fluoride and sulfate ions determination and by ICP-OES for calcium carbonate determination

GLP compliance:

no

Type of method:

other: The sample is added to water until there is no dissolved product then the clear solution in analysed

Key result

Water solubility:

0.25 g/L

Remarks on result:

other: CaCO3 solubility

Key result

Water solubility:

0.009 g/L

Remarks on result:

other: CaF2 solubility

Key result

Water solubility:

2.55 g/L

Remarks on result:

other: CaSO4 solubility

Conclusions:

The composition of test item solution has been determined by two analytical methods. The composition is :
CaCO3 0.25 g/l
CaF2 0.009 g/l
CaSO4 2.55 g/l

Executive summary:

In order to determine test sample composition, the test item was added to water until there is no dissolved product.

Then the clear solution is injected on ionic chromatography for fluoride and sulfate ions determination and by ICP-OES for calcium carbonate determination.

The composition of test item solution obtained is :

concentration of CaCO₃: 0.25 g/l

concentration of CaF₂: 0.009 g/l

concentration of CaSO₄: 2.55 g/l

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

26 January 2010 to 04 March 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Water solubility:

0.017 g/L

Temp.:

20 °C

pH:

> 9 - < 9.4

Remarks on result:

other: Mean of 5 samples

Details on results:

The results for Samples 1 to 3 suggested that the water solubility was shaking time dependent; therefore, extra testing was carried out using longer shaking periods (Samples 4 and 5). However, the overall results for Samples 1 to 5 indicated that this was not the case.

Table 1: Concentration of test material in the sample solutions

Sample No.	Time shaken at ~30 °C (hours)	Time equilibrated at 20 °C (hours)	Concentration (g/L)	Solution pH
1	24	24	1.67 x 10^-2	9.4
2	48	24	1.63 x 10^-2	9.4
3	72	24	2.06 x 10^-2	9.4
4	96	24	1.45 x 10^-2	9.0
5	120	24	1.51 x 10^-2	9.0

Conclusions:

The water solubility of calcium carbonate (conventional) has been determined to be 0.0166 g/L of solution at 20.0 ± 0.5 °C and pH between 9 to 9.4. Based on this value, calcium carbonate is considered as slightly soluble in water.

Executive summary:

The water solubility of calcium carbonate have been determined with the shake flask method according to a recongnised guideline (OECD 105) and under GLP.

No deviation from the guideline has been observed during the study.

The concentration of calcium carbonate in the test sample have been determined with ICP-MS.

The water solubility of calcium carbonate was been determined to be 0.0166 g/L of solution at 20.0 ± 0.5 °C and pH between 9 to 9.4.

Reference 3

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2010-04-12 to 2010-04-16

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

yes

Remarks:

In place of centrifugation, the solution was filtered with filter paper prior to determination of the mass concentration of the substance in aqueous solution.

GLP compliance:

no

Type of method:

flask method

Water solubility:

2.4 g/L

Temp.:

20 °C

pH:

7.7

Details on results:

In the first preliminary test, the sample remained essentially undissolved. At the end of the second preliminary test, the sample appeared totally dissolved. From the results of the preliminary testing, that the water solubility of calcium sulphate dihydrate was between 1 and 10 g per litre of water.
In the definitive test, no tendency to concentration increase could be detected, so the average value of the 3 samples was taken to determine the solubility. It was observed that magnetic stirring increased the temperature slightly. During pH measurement, the temperature was measured from the filtrates allowing direct measurement during magnetic stirring. The temperature of the samples was found to increase from 20 to 21-22°C, which was not thought to produce noticeable effects on the solubility of the test material.

  Table 1: tabulated water solubility data

Sample	Ca in g/L		SO4 in g/L		pH
	Measurements	Mean value	Measurements	Mean value
Flask 1	0.724	0.725	1.911	1.9	7.7
	0.729		1.913		7.7
	0.723		1.9		7.6
Flask 2	0.731	0.728	1.873	1.86	7.7
	0.723		1.854		7.6
	0.729		1.881		7.6
Flask 3	0.724	0.723	1.735	1.73	7.7
	0.724		1.724		7.6
	0.721		1.719		7.7

The water solubility was determined from the concentration of calcium as the value calculated by using the solubility of SO4 instead of Ca produces a slightly higher value, this is due to a small interference by small quantities of sodium, potassium, magnesium sulfates explaining this small overestimation.

Conclusions:

The water solubility of CaSO4 was determined to be 2.4 g/L at 20°C and with a pH value of 7.7. Based on this value, calcium sulphate is considered as soluble.

Executive summary:

The water solubility of Calcium sulfate have been determined with the flash flask method according to a recognised guideline (OECD 105). No deviation which can affect the quality or the results of this study has been observed.

The water solubility of the test substance was determined based on measured concentrations of calcium with ionic chromatography. The water solubility of calcium sulfate is 2.4 g/L at 20°C and with a pH value of 7.7.

Reference 4

Endpoint:

water solubility

Type of information:

other: Handbook data

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

peer reviewed

Principles of method if other than guideline:

Data is from handbook, no details are provided.

GLP compliance:

no

Water solubility:

6.6 mg/L

Temp.:

20 °C

Water solubility:

11 mg/L

Temp.:

20 °C

Details on results:

The water solubilities of calcium carbonate are:

Aragonite and calcite: 6.6 mg/L at 20 °C
Vaterite: 11 mg/L at 20 °C

Conclusions:

The water solubilities of calcium carbonate are:

Aragonite and calcite: 6.6 mg/L at 20 °C
Vaterite: 11 mg/L at 20 °C

Executive summary:

The water solubility of calcium carbonate in the reliable CRC handbook is :

6.6 mg/l for aragnite and calcite and 11 mg/l of vaterite at 20°C

Reference 5

Endpoint:

water solubility

Type of information:

other: Handbook data

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

peer reviewed

Principles of method if other than guideline:

Data is from handbook, no details are provided.

GLP compliance:

not specified

Type of method:

other: no data

Water solubility:

0.015 g/L

Temp.:

18 °C

Value from generally accepted authoritative secondary source. No data available for pH value.

Conclusions:

The water solubility of CaF2 is 0.015 g/l at 18.0°C

Executive summary:

The water solubility of CaF2 is 0.015 g/l at 18.0°C in the reliable Merck Index handbook.

Reference 6

Endpoint:

water solubility

Type of information:

other: Handbook data

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

peer reviewed

Principles of method if other than guideline:

Data are from handbook, no details are provided.

Water solubility:

2.7 g/L

Temp.:

20 °C

Details on results:

The steady state concentration of calcium sulfate in water is 2.05 g/L, for all three forms. There is the possibility of short-term over-saturation effects, particularly for the hemihydrate form, leading to apparent water solubilities of:

Anhydrite: 2.7 g/L (at 20°C)
Hemihydrate: 8.8 g/L (at 20°C)
Dihydrate: 2.1 g/L (at 20°C)

Conclusions:

The solubility of calcium sulfate (anhydrite form) is 2.7 g/L

Executive summary:

The water solubility of calcium sulfate (anhydrite form) is 2.7 g/l in reliable handbooks

Description of key information

In order to determine test sample composition, the test item was added to water until there is no dissolved product and mix for 1 hour.

Then the clear solution is injected on ionic chromatography for fluoride and sulfate ions determination and by ICP-OES for calcium carbonate determination.

The composition of test item solution obtained is :

concentration of CaCO₃: 0.25 g/l

concentration of CaF₂: 0.009 g/l

concentration of CaSO₄: 2.55 g/l

Additional information

The test item is a reaction mass, for this category of test item the concept of water solubility as known for pure substance is not applicable. As described in the ECHA Guidance on information requirements and chemical safety assessment R7.a, the concentration of the aqueous phase has been determined after 1 hour a mixing.

The water solubilities of each constituents of the test item are given as indicative information.