Sampling Techniques - Day 3 Flashcards
These are zones of increased content of
chemical elements in natural formations
associated with deposits of useful minerals.
Halos of Dispersion
This arise in the surrounding rock with the formation of the mineral body
Primary halo
Form in the products of decomposition of rock, and also in soil, water, plants, and the surface atmosphere as a result of supergene processes
taking place on the land surface
Secondary halo
The four types of secondary dispersion halo
Mechanical Halos
Saline Halos
Gaseous Halos
Biogeochemical
It is a sampling method where a specimen
is picked up from a portion of mineralized
outcrop/ore body.
Grab sampling
The grab samples are taken and analyzed to obtain a preliminary idea about:
the nature and grade of whole deposit and appreciate metal content
suitable sampling method for bedded, banded and vein type of deposits
Channel/Groove/Trench Sampling
Channel/Groove/Trench Sampling method consists of cutting channels across the face of exposed ore and collecting ___________________ from each channel to make a sample
chips, fragments, and dust
In conducting channel sampling, the outcrop is first:
cleared from unwanted materials
T or F. Can rock faces be trimmed at the cutting point of the deposit?
True. Rock face may be trimmed if necessary.
The location of the channel in channel sampling is market by:
a set of parallel lines
The excavated material from channel sampling is collected, pulverized carefully, and the sampling site is:
labeled
sampling method used for hard or uniform ores where it is difficult to cut channels
Chip or Point sampling
In chip or point sampling, what material is being sampled?
blasted, broken material
Chip or Point sampling are collected by using a small series of chips of rocks on a ___________ pattern from the working face in ____________ intervals.
regular grid pattern; regular intervals
In chip or point sampling, the shape of the grid is adopted to the deposit’s
morphology and structure
The main advantage of this sampling is its high productivity
Chip or Point Sampling
Involves cutting of pieces of ore and rock from exposed faces
of ore and waste. The faces may be natural outcrops or faces
exposed in surface trenches and pits or in the backs, walls,
and floors of development openings and stopes.
Face or Muck or Lump Sampling
In Face or Muck or Lump Sampling, face samples may be taken by either:
by cutting grooves or channels of uniform width and depth across the face or sections of the face or;
by picking off small pieces all over the face, more or less at random.
This type of sampling method is used in checking of the
reliability of other types of samples and sometimes may be
taken to determine a correction factor for use in an estimate
based on samples of other types.
Bulk Sampling
How are samples taken in bulk sampling?
by blasting down drift blocks or a section in a stope, or; obtaining a sample of several tons either from
trench, pit, channel or from the run-of-mine
Collection and analysis of silt,
sand, mud, clay in a stream or
river bed, either dry or wet
Stream Sediment Sampling
Usually employed as an early stage exploration tool to cover large areas relatively quickly in the hope of identifying smaller areas of interest to be followed up with prospecting and more detailed (and costly) sampling techniques.
Stream Sediment Sampling
This method is more convenient for the determination of the deposit’s boundaries. Here, samples consists of the cuttings from drill holes.
Drill Hole Sampling
What are the two types of errors
Random and Systematic
What are the three common sampling patterns
Regular, Staggered, Equidistant
Simplest grid design; all the samples are equally spaced apart vertically and horizontally
Regular Grid
Samples are equally apart horizontally. Every other sample line is offset one half sample spacing which decreases the diagonal spacing between samples.
Staggered Grid
Each sample has same distance of away from each surrounding sample. This pattern is sometimes called a triangular grid because 3 nearest samples form an equilateral triangle.
Equidistant Grid
