Stockpiles, sampling from

The theoiy enables a reasonable estimate of sample quantity needed to attain specified accuracy of a composition variable. The result is an ideal quantity—not realized in practice. Actual quantities for practical estimation are larger by an appropriate multiple to account for the reality that material is incompletely mixed when stored in stockpiles or carried on conveyors. Sample quantity to accommodate incompletely mixed sohds can be specified through evaluating variance by autocorrelation of data derived with a series of stockpile samples, or from multiple sample extractions taken from a moving stream (Gy, Pitard). 

Determine the sampling point locations within each segment with a random number generator. Sample each segment either manually or with an excavator or backhoe bucket. If the stockpile is stable and safe to climb on, use a hand auger or a hand trowel to obtain samples from below the surface at the top and sides of the stockpile. 

Four soil samples from a contaminated soil stockpile... 

Sampling from deep hoppers and open stockpiles is the most difficult and inaccurate of all sampling operations and it should be avoided whenever possible. 

A procedure for sampling from stockpiles is described in BS 812 [6.3]. Sampling from stockpiles should, however, only be adopted as a last resort, as experience shows that the precision of the results so obtained is generally much lower than those of alternative procedures. 

Sampling of RA from a lorry load or stockpiles is carried out as in aggregate sampling and in accordance to relevant national specifications, such as CEN EN 932-1 (1996), ASTM D 75 (2009), AASHTO T 2 (2010) or other specifications. However, sampling from stockpiles (feedstock) requires that the number of samples should be sufficient CEN EN 13108-8 (2005) recommends 1 for every 500 t of feedstock, rounded off upwards, with a minimum of 5. 

ASTM D-6610. Standard Practice for Manual Sampling Coal from Surfaces of a Stockpile. 

Samples of South Blackwater and Ensham coal of +16.0 mm size were collected separately, from the stockpiles of the Gladstone Port. Before testing, both types of coals were sieved to obtain a —76.2 + 50.8 mm sized samples for the drop tests. The sample was placed inside the released hopper, which was raised by overhead crane. A sample of 10 kg was dropped each time onto an enclosed horizontal steel plate, conveyor belt and coal stockpile. The dropped coal was sieved to remove the fines (-16.0 mm size). In this way the percentage of fines produced at each drop were determined. The calculation methodology for fines percentage was given in Sahoo et al. [2],... 

We need to make a decision related to the disposition of soil that has been excavated from the subsurface at a site with lead contamination history. Excavated soil suspected of containing lead has been stockpiled. We may use this soil as backfill (i.e. place it back into the ground), if the mean lead concentration in it is below the action level of 100 milligram per kilogram (mg/kg). To decide whether the soil is acceptable as backfill, we will sample the soil and analyze it for lead. The mean concentration of lead in soil will represent the statistical population parameter. 

Because historical data for the soil is not available, to estimate the number of samples for the stockpile characterization, we collect four preliminary samples and analyze them for lead. The concentrations are 120, 60, 200, and 180 mg/kg, with the average concentration of 140 mg/kg and the standard deviation of 63 mg/kg. We use Equation 11, Appendix 1, for the calculation of the estimated number of samples. Using a one-tailed confidence interval and a probability of 0.05, we determine the Student s t value of 2.353 for 3 degrees of freedom (the number of collected samples less one) from Table 1, Appendix 1. 

Composite samples are typically collected for soil stockpile or surface area characterization. Twenty-four-hour composite samples of water may be collected with automated composite samplers from streams or process piping composite samples may be made of several grab samples collected from different depths in a soil boring. 

Thirteen core samples were used from the earlier study of the environmental impact of phosphogypsum production (/). The sample identifications are the same as in that work A through I each represents an individual stockpile, and 1,2, and 3 represent different cores on the same stockpile. Five additional core samples were obtained for this study. The new samples were taken only through a short section approximately 3 m above and 3 m below the interface with the ground surface. The samples contained phosphogypsum or soil. The sample identifications are the same as before A, B, F, and H refer to the same stockpile as in Ref / 1 and 2 refer to different cores on the same stockpile, but the samples are differentiated from the former samples by -2, for example, F2-2. All sample depths are measured from the tops of the stockpiles of phosphogypsum. 

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