SAMPLING and SAMPLE PREPARATION PPT

Question 1

STEPS in an analysis

Answer 1

memorisa yot

Question 2

In statistics and quantitative research methodology, a ____ is a set of individuals or objects collected or selected from a statistical population by a defined procedure

Answer 2

Sample

Question 3

In extraction industry, it is a small portion of a whole mass that accurately represents the whole mass

Answer 3

Sample

Question 4

• The process of taking a small portion of a material such that the consistency of the portion shall be representative of the whole
  • the most difficult step in an analysis and the source of greater error
  • is a progressive process in which the original material is reduced in quantity to the final mass of sample convenient for analysis

Answer 4

SAMPLE COLLECTION

Question 5

• is the PRE -REQUISITE of effective analysis

Answer 5

SAMPLE COLLECTION

Question 6

• the most difficult step in an analysis and the source of greater error

Answer 6

SAMPLE COLLECTION

Question 7

“If a sample is correct and sufficiently reproducible, it automatically qualifies as representative”

Answer 7

-(D. Francois -Bongarcon and P. Gy)

Question 8

FACTORS FOR CONSIDERATION IN SAMPLING

Answer 8

1. Uniformity of Composition of the Bulk ( Homogeneity)

Question 9

SOLUTION???

“Ore which breaks into lumps of large variation of sizes are probably of different composition”

Answer 9

crushing the materials into fine powder and thorough mixing is desirable to obtain a true sample

Question 10

CLASSIFICATIONS OF MATERIALS

_____(1)
* Liquids – water, oil, molten metals and slags
* Gases – flue gas, producer gas

Answer 10

Fluids

Question 11

CLASSIFICATIONS OF MATERIALS

-Metals, alloys

Answer 11

Tough or Sectile Materials

Question 12

CLASSIFICATIONS OF MATERIALS

Ores, fluxes, coal, brittle metals, alloys, etc

Answer 12

Brittle or Frangible Materials

Question 13

GENERAL PRINCIPLES in SAMPLING

Necessary to be mixed thoroughly and withdraw any convenient portion.

Answer 13

Fluids

Question 14

GENERAL PRINCIPLES in SAMPLING

Quantity to be taken depends upon the value and uniformity of the material and the size of the largest particles.

Answer 14

Fragmental Materials

Question 15

“the weight taken for sample shall be proportional to the square of the diameter of the largest particle“

Answer 15

Prof. R.H. Richards’ (MIT) Rule

Question 16

Surface Sampling

this method consist of cutting channels across the face of exposed ore and collecting the resulting chips, fragments and dust from each channel to make a sample

Answer 16

Channel Sampling

Question 17

Surface Sampling

• a series of chips of rock is taken either in a continuous line across the exposure or at random intervals over a face.
• used for hard or uniform ores where it is difficult to cut channels

Answer 17

Chip Sampling

Question 18

Surface Sampling

• a grab-sample of the muck pile after blasting is sometimes taken instead of a channel sample of a face. It picks pieces of rock of convenient size.
• it is very simple , quick and cheap procedure but the accuracy of this method is very low.

Answer 18

Muck Sampling

Question 19

Surface Sampling

• a shovelful of ore or a series of pieces selected either at random or according to a pre-arranged system is taken from each car that comes from the face. This gives a fairly large samples.

Answer 19

Car Sampling

Question 20

Surface Sampling

• usually done at established or grid points where soil/rock chips, sediments, water, mud, etc. are collected for analysis.

Answer 20

Geochemical Sampling

Question 21

Surface sampling

is done to further determine the mining and metallurgical properties of the deposit such as:
-grade of ore;
-degree of homogeneity if mineralization;
- rock hardness and strength;
- ore and gangue mineralogy & their variations;
- grain size of mineral;
- response to ore drilling process.

Answer 21

Bulk Sampling

Question 22

PRIME purpose of Bulk Sampling???

Answer 22

To confirm grade indicated by prior sample data from drill holes or workings

Question 23

BASIC FLOW DIAGRAM OF BULK SAMPLING ARRANGEMENT

Answer 23

MEMORISA YOT

Question 24

Subsurface Sampling

horizontal and vertical excavation are made to collect mineral samples located beneath the surface

Answer 24

Excavation of tests Pits/Trenches

Question 25

# Subsurface Sampling -collection of crushed, fines and rock cores beneath the surface using a drilling equipment. -The drilling method could be either rotary-percussive; rotary, diamond core, churn, wash boring, hammer drilling, auger, and shot drilling.

Answer 25

Drilling

Question 26

Goal of laboratory sample preparation

Answer 26

to provide, without sample loss, representative aliquants that are free of laboratory contamination that will be used in laboratory analysis to determine the concentration of an analyte.

Question 27

THREE STEPS INVOLVED IN PROCESSING THE SAMPLES

Answer 27

1. Preparing Laboratory Samples 2. Measuring the Samples (Defining Replicate Samples) 3. Dissolving the Samples

Question 28

# Preparing Laboratory Sample A solid laboratory sample is ground to decrease particle size, mixed to ensure homogeneity, and stored for various length of time before analysis begins.

Answer 28

Crushing

Question 29

# Preparing Laboratory sample (to reduce the particle size in order to ensure homogeneity and to facilitate attack by reagents.)

Answer 29

Grinding

Question 30

# Preparing Laboratory Sample (to obtain laboratory sample) – Coning and Quartering – Riffle Splitter (Mechanical Device) - consists of a series of chutes directed alternately to opposite sides. The alternating chutes divide the sample into many portions, which are then recombined into two.

Answer 30

Reducing Sample Size

Question 31

# MEASURING THE SAMPLE The amount of the sample is expressed most often as

Answer 31

Weight or volume

Question 32

# MEASURING THE SAMPLE ____ samples are often analyzed on a dry basis and must be dried in an oven at ____ to ____ degree Celsius for ____ to ____ hr and cooled in a desiccator before weighing

Answer 32

Solid 105-110 degree celcius 1 to 2 hr

Question 33

# MEASURING THE SAMPLE are portion of a material of approximately the same size that are carried through an analytical procedure at the same time and in the same way

Answer 33

Replicate Samples

Question 34

# DISSOLVING THE SAMPLES used for samples containing soluble salts

Answer 34

Water

Question 35

# DISSOLVING THE sAMPLE used for samples that will not dissolved in water such as o Non-oxidizing acids: HCl, HBr, H3PO4, dilute. H2SO4, dilute HClO4 o Oxidizing acids: hot and concentrated H2SO4, ot and concentrated HClO4, HNO3, aqua regia (mixture of HCl & HNO3) are used for stubborn samples, HF used for silicate materials.

Answer 35

Acids

Question 36

# ACIDS Non-oxidizing acids | 5 sila

Answer 36

HCl, HBr, H3PO4, dilute. H2SO4, dilute HClO4

Question 37

# ACIDS Oxidizing acids

Answer 37

hot and concentrated H2SO4, hot and concentrated HClO4, HNO3, aqua regia (mixture of HCl & HNO3) are used for stubborn samples

Question 38

# ACIDS aqua regia (mixture of ____) are used for ____ samples

Answer 38

HCL & HNO3 stubborn

Question 39

# DISSOLVING THE SAMPLES used for organic samples that do not dissolved in water

Answer 39

Organic Solvents

Question 40

typically used for the dissolution of most metals, oxides, sulfides, phosphates, and carbonates.

Answer 40

HCl and HBr

Question 41

is capable of dissolving most metals, with the exception of gold and platinum

Answer 41

HNO3

Question 42

To dissolve Gold and Platinum, a ____ volumetric mixture of HCl and HNO3 (also known as ____) can be used.

Answer 42

3:1 Aqua Regia

Question 43

HCl and HBr digestions are typically performed with a concentration of ____% and ____%, respectively

Answer 43

37% and 48-65%

Question 44

When using hot acids, HCl has a constant boiling composition of ____% at ____◦C

Answer 44

20% at 109degree celcius

Question 45

HBr has a constant boiling composition of ____% at ____◦C

Answer 45

48% 124 degree celcius

Question 46

A ____% ____ solution is often used for the dissolution of silicates

Answer 46

50% HF

Question 47

the process of dissolving a sample in a molten solvent known as flux that has acidic, basic, or oxidizing properties. This is carried out by mixing finely ground samples with solid flux in an inert metal crucible and heating until the flux melts, at which time it becomes very reactive and dissolves the sample. After a period, the melt is cooled and dissolved in water or diluted aqueous acid.

Answer 47

Fusion

Question 48

# Eliminating Interference In the case of a liquid suspension, ____or ____ is often performed prior to analysis to remove any solid particles.

Answer 48

Filtration or Centrifugation

Question 49

# Eliminating Interference In the case of a solution, there are many methods available for isolating analytes, including ____, ____, or ____

Answer 49

Complexation, separation, or extraction

Question 50

Reasons for the performance of these procedures prior to analysis:

Answer 50

* to remove any species that may cause interferences in the particular analysis or * to provide a means of concentrating the analyte prior to analysis

Question 51

Methods of Eliminating Interference

Answer 51

1. Extraction 2. isolation of particular components 3. transference of compounds from solid/liquid to solvent/phase

Question 52

# Types of extraction are commonly used for analyte isolation: ____ In ____, the two phases are both liquid and are immiscible in each other (e.g., an aqueous phase and an organic phase), creating two layers with a distinct boundary.

Answer 52

liquid/Liquid extraction

Question 53

The reaction between the two species ( interfering species with a chelating agent) forms a stable complex which cannot undergo certain chemical reactions that are essential for quantification of the analyte.

Answer 53

Complexation Reaction ( Masking )

Question 54

# Types of Extraction are commonly used for analyte isolation: ____ - the partitioning of an analyte between the liquid in which it is dissolved and a solid support. These Such extractions are typically based upon adsorption of the solute onto the solid.

Answer 54

Solid-Phase extraction

Question 55

Precipitation reactions, an insoluble complex is selectively formed with either the interfering species or the analyte itself. Once the precipitate is formed, it can be removed and discarded in the case of an interfering species or analyzed in the case of the analyte

Answer 55

Separation