Regular Salt MGS9205G.pdf

MGS-92-05G

(Page 1 of 6)

(Rev.04/13/22) CL

SODIUM CHLORIDE MGS-92-05G

1.0 SCOPE. This specification covers sodium chloride, obtained from natural deposits (rock salt) or produced by man (evaporated, solar, other) for use as a de-icer for maintenance purposes.

2.0 MATERIAL.

2.1 Chemical Composition. The minimum percent sodium chloride (NaCl) shall be as follows for the material ordered, when tested in accordance with MoDOT Test Method T32 included in Annex A of this specification.

Name Minimum % NaCl

95% Sodium Chloride 95

2.2 Gradation. The gradation shall conform to the following requirements:

Sieve Size Percent Passing (by weight)

1/2 inch 100 3/8 inch 95 - 100 No. 4 15 - 95 No. 8 5 - 65 No. 30 0 - 15

2.3 Condition. The sodium chloride shall arrive at the delivery point in a free-flowing and usable condition.

2.4 Moisture. The moisture content at the delivery point shall not exceed 2.0 percent based on dry weight. Visual appearance of excess water will result in immediate rejection.

2.5 Foreign Material. Sodium chloride shall be relatively free from any foreign material at the delivery point. Residue from truck beds such as coke, grain, or other materials not germane to sodium chloride will be cause for rejection. Any oversize foreign material will result in immediate rejection.

3.0 PACKAGING.

3.1 The sodium chloride shall be delivered in bulk lots.

3.2 The supplier shall furnish the truck driver a copy of the bill of lading, manifest, or truck ticket to be delivered to the Missouri Department of Transportation personnel prior to unloading, showing the following information regarding the shipment:

(a) Consignee.

(Rev. 04-13-22) CL

(b) Destination.

(c) Type of Material (including the percent Sodium Chloride).

(d) Purchase Order Number.

(d) Truck number and weights of truck before and after loading.

(f) Date loaded.

(g) Name and Location of the Source.

(h) A Certification Statement.

3.2.1 The certification statement shall be signed by an authorized representative of the Supplier and substantially as follows:

"This certifies that the Sodium Chloride in this shipment complies with Missouri Department of Transportation specifications and the weights shown hereon were obtained on scales approved by and/or certified by the State of Missouri and are correct within the specified scale requirements."

3.2.2 The requirements for platform scales for weighing Bulk Sodium Chloride are shown in Annex B of this specification.

4.0 ACCEPTANCE.

4.1 A lot shall consist of that quantity of material ordered for delivery to one location.

4.2 Acceptance of the material will be based on satisfactory compliance with this specification as determined by samples and inspection deemed necessary by the engineer or engineer’s representative at the delivery site. A sample shall be obtained at a minimum of once per 500 tons delivered.

4.3 If samples fail to meet the material requirements on the basis of an initial sample, two additional samples shall be taken from the lot and tested. Both of the additional samples must meet the requirements, or delivered material up to the sample point and between 500 ton sampling intervals will be subject to price deductions.

4.4 The department will not accept loads which exceed the legal limits. Overweight loads that are emptied before rejection will have the tonnage in excess of the legal weight deducted from the invoice.

4.5 In addition to other requirements, 95% Sodium Chloride material shall be specifically delivered to a location designated by receiving personnel, and any contamination with existing lower percentage sodium chloride salt as a result of delivery will be cause for rejection or payment at the lower sodium chloride content salt rate, at the department’s option.

(Rev. 04-13-22) CL

ANNEX A

TEST METHOD MODOT T32

DETERMINATION OF PURITY OF SODIUM CHLORIDE

1.0 SCOPE. This method describes a procedure for determining the percent sodium chloride in commercial grades of sodium chloride.

2.0 REAGENTS AND APPARATUS.

2.1 Millivolt meter equipped with a combination chloride electrode.

2.2 Nitric Acid (HNO3), chloride free, 1.42 specific gravity.

2.3 Sodium Chloride (NaCl), Reagent Grade, dried at 105-110C for 1 hour prior to use.

2.4 Silver Nitrate (AgNO3), Reagent Grade.

2.5 A source of chloride-free distilled or deionized water.

3.0 PREPARATION OF STANDARD SOLUTIONS.

3.1 Standard Sodium Chloride Solution (0.0100N). Weigh 0.5844 g dried NaCl, dissolve in distilled water and dilute to 1L.

3.2 Standard Silver Nitrate Solution (0.01N). Weigh 1.699 g AgNO3, dissolve in distilled water and dilute to 1L. Standardize to the nearest 0.0001 N against 0.0100 N NaCl.

4.0 PROCEDURE.

4.1 Using a suitable sample splitting technique, divide the salt, as received, to obtain a representative sample of about 75 g. Grind the entire 75 g sample to pass a No. 50 mesh sieve, dry at least 3 hours at 105-110C and cool to room temperature in a desiccator. Weigh the sample to the nearest 0.1 mg and transfer to a 1000-mL beaker. Add approximately 500 mL of distilled water and 20 mL of HNO3. Heat near boiling 1 hour, occasionally stirring and crushing any insoluble matter against the bottom of the beaker with the flattened end of a stirring rod. Cool to room temperature, quantitatively transfer to a 1000-mL volumetric flask and dilute to volume with distilled water. Transfer a 10-mL aliquot to a 1000-mL volumetric flask and dilute to volume with distilled water.

4.2 Transfer a 10-mL aliquot to a 250-mL beaker, adding 90 mL of distilled water and 1 mL of HNO3. Determine the chloride concentration by potentiometric titration with the standard silver nitrate solution.

(Rev. 04-13-22) CL

5.0 CALCULATION AND REPORT.

5.1 Report percent sodium chloride to the nearest 0.1% as follows:

% Sodium Chloride (NaCl) = A x C x 584.5 x 100

D

Where:

A = Milliliters of AgNO3 solution to titrate sample

C = Normality of AgNO3 solution

D = Grams of sample

(Rev. 04-13-22) CL

ANNEX B

SPECIFICATIONS FOR PLATFORM SCALES

FOR WEIGHING BULK SODIUM CHLORIDE

1.0 Equipment for weighing of bulk Sodium Chloride shall consist of accurate and reliable platform scales approved by the Missouri Department of Transportation.

2.0 Calibration shall be to within an accuracy of 0.4 percent of the load applied, regardless of the location of the load on the platform. The value of the smallest unit of graduation on a scale shall be not greater than 20 pounds. Sensitivity requirements of scales not equipped with balance indicators shall be twice the value of the minimum graduated interval on the weigh beam, or 0.2 percent of the nominal capacity of the scale, whichever is less. For scales equipped with balance indictors, the sensitivity requirement shall be the value of the minimum graduated interval on the weigh beam.

3.0 When equipment to be weighed is of such length that all axles cannot be weighed simultaneously, a level area of portland cement concrete or asphaltic concrete pavement shall be provided permitting those axles not on the scale platform to be on the pavement during the weighing operation. the approach shall be the same width as the platform and of sufficient length to insure the level positioning of vehicles during weight determinations. The weighing shall be performed with all brakes released. When equipment to be weighed is equipped with an air bag suspension unit on any axle, the equipment including semi-trailers or pup trailers shall be weighed on platform scales of sufficient size to weigh all axles of the combination simultaneously.

4.0 Scales shall have been calibrated within the six month period immediately prior to any material being delivered or any time the Missouri Department of Transportation's representative has cause to question the accuracy of the scale. A scale acceptance shall be based on one of the following:

(a) A valid certification or seal of approval by the Division of Weights and Measures of the Missouri Department of Agricultural will be acceptable.

(b) A valid certification or seal of approval by a State of Missouri duly appointed "sealer of weights and measures" in cities or counties of seventy-five thousand population or more will be acceptable.

(c) Certification of calibration from a commercial scale service company showing that the scale meets the requirements of these specifications. The Supplier shall furnish the certification of calibration to the Missouri Highway and Transportation Department's representative.

4.1 Regardless of the form of acceptance, the calibration shall be within the accuracy requirements specified herein and the scales shall meet all requirements of these specifications.

(Rev. 04-13-22) CL

4.2 Verification of a platform scale may be required of a hauling unit on another recently calibrated and certified scale.

4.3 All cost incurred in obtaining a certification of calibration or verification shall be borne by the Supplier.