S.I. No. 260/1953:

STANDARD SPECIFICATION (GROUND LIMESTONE) ORDER, 1953

STANDARD SPECIFICATION (GROUND LIMESTONE) ORDER, 1953

I, SEAN F. LEMASS, Minister for Industry and Commerce, in exercise of the power conferred on me by subsection (3) of section 20 of the Industrial Research and Standards Act, 1946 (No. 25 of 1946), hereby order as follows :

1. This Order may be cited as the Standard Specification (Ground Limestone) Order, 1953.

2.--(1) The specification set forth in the Schedule to this Order is hereby declared to be the standard specification for Ground Limestone.

(2) The said standard specification may be cited as Irish Standard 53 : 1953 or as I.S. 53 : 1953.

SCHEDULE

In this specification, the letters I.S., when followed by two sets of numbers, refer to the Irish Standard of which the first is the serial number and the second the year of its promulgation by the Minister for Industry and Commerce.

SCOPE

1. This specification covers the requirements of ground limestone for the improvement of land for agricultural purposes.

COMPOSITION

2. For the purpose of this specification ground limestone shall be crushed natural limestone consisting mainly of calcium carbonate or of calcium and magnesium carbonates.

MOISTURE CONTENT

3. The moisture content of ground limestone, when determined as described in Appendix A, shall be not more than 2·5 per cent.

TOTAL NEUTRALISING VALUE

4. The total neutralising value of ground limestone, when determined as described in Appendix B, shall be not less than 90 per cent.

FINENESS

5. Ground limestone, when tested for fineness as described in Appendix C, shall all pass through a ¹/₈ in. test sieve and not less than 35 per cent. of it shall pass through a No. 100 test sieve. The test sieves shall conform to I.S. 24 : 1950.

SAMPLING FOR TESTS

6. Approximately equal portions of the material shall be taken by means of a sampling spear, spade or trowel, from different parts in the bulk of the material so as to be reasonably representative of the whole. The number of portions to be taken shall be,

(a) where the quantity is 10 tons or less -- 10 portions,

(b) where the quantity exceeds 10 tons but does not exceed 20 tons -- 20 portions,

(c) where the quantity exceeds 20 tons, but does not exceed 100 tons -- 20 portions, plus one portion for each five tons in excess of 20 tons,

(d) where the quantity exceeds 100 tons -- 36 portions plus one portion for each 10 tons in excess of 100 tons.

The portions shall be thoroughly mixed and quartered down to give a sample for testing of not less than ½ lb. in weight. The sample for testing shall be enclosed immediately in a clean dry air-tight container which shall be sealed and marked with sufficient information to identify the sample.

APPENDIX A.

Determination of Moisture Content.

A representative portion of the sample shall be weighed with precautions against loss of moisture. It shall then be dried in a ventilated oven maintained at a temperature between 100-105 ° C., until two successive weighings after cooling in a desiccator, at intervals of not less than 3 hours in the oven, show an increment of loss of not more than 0·1 per cent. of the original weight. The loss in weight calculated to the nearest 0·5 per cent. as a percentage of the original weight shall be taken to be the moisture content.

APPENDIX B.

Determination of the Total Neutralising Value.

A representative portion of the sample shall be dried in an oven maintained at a temperature between 100-105 °C., until two successive weighings after cooling in a desiccator, at intervals of not less than 3 hours in the oven, show an increment of loss of not more than 0·1 per cent. of the original weight. The material shall then be ground to a degree of fineness which permits the whole amount to pass through a No. 60 test sieve conforming to I.S. 24 : 1950. The ground material shall be kept in an air-tight container. An amount, 1 g., shall be weighed to an accuracy of 1 mg., and this amount shall be placed in a 250 ml. Erlenmeyer flask to which 50 ml. of 0·5 N hydrochloric acid shall be added. A small funnel shall be placed in the neck of the flask. The contents shall be heated, maintained at gentle boiling for five minutes and then cooled.

The residual acid shall be determined by titration against 0·25 N sodium hydroxide using phenolphthalein as indicator.

The weight of calcium carbonate equivalent to the weight of hydrochloric acid which has been neutralised by the ground limestone, shall be calculated and shall be expressed as a percentage of the weight of the ground limestone. This result shall be taken to be the total neutralising value.

APPENDIX C.

Determination of Fineness.

A quantity of the dried material, approximately 100 g. in weight, shall be weighed to 0·1 g. accuracy. This amount shall be sifted through the 1/8 in. test sieve specified. Soft lumps shall be broken down with the fingers but shall not be rubbed on the sieve. Any residue remaining on the 1/8 in. test sieve shall be noted. The material which has passed through this sieve shall be transferred to the No. 100 test sieve specified and shall be sifted continuously for ten minutes with occasional tapping of the sides of the sieve.

The material which has passed through the No. 100 test sieve shall be weighed to 0·1 g. accuracy and the result shall be expressed as a percentage of the weight of dry material taken for the test.

GIVEN under my Official Seal, this 24th day of July, 1953.

(Signed) SEAN F. LEMASS

Minister for Industry and Commerce.