FINALS KRAZY Flashcards
These are zones of increased content of chemical elements in natural formations associated with deposits of useful minerals
halos of dispersion
2 types of halos of dispersion
primary halo
secondary dispersion halo
arise in the surrounding rock simultaneously with the formation of the mineral body; internal process
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 dispersion halo
types of secondary dispersion halo
mechanical
saline
gaseous
biogeochemical
–dispersed in the solid phase
–form during decomposition of deposits with stable primary or secondary minerals in the zone of weathering, as their fragments progressively disintegrate and particles of the useful mineral are diffused with eluvial and talus deposits
mechanical halos
–dispersed in the form of soluble compounds
–in capillary solutions of rock and subterranean water
–form deposits of mineral salts, certain metal sulfates, and other easily soluble primary and secondary minerals as the result of diffusion, capillary elevation, evaporation of mineralized solutions, sorption, and biogenic accumulation of the chemical elements of the mineral
saline halos
–typical for deposits of petroleum and natural fuel gases, helium, and radioactive ores
–many ore deposits are associated with halos of dispersion of mercury vapor and other gases
gaseous halos
–form in plants in the region of the deposit, which contain increased quantities of the valuable elements and their associated minerals.
biogeochemical halos
7 common types of sampling methods
- Grab Sampling
- Channel or Groove or Trench Sampling
- Chip or Point Sampling
- Face or Muck or Lump Sampling
- Bulk Sampling
- Stream Sediment Sampling
- Drill Hole Sampling
not considered as true sampling, but for early exploration stages, it may be a basis for determining initial composition of the target mineral body
grab sampling
–a specimen is picked up from a portion of mineralized outcrop/ore body
–samples are taken and analyzed to obtain a preliminary idea about the nature and grade of whole deposit and to know appreciate metal content
grab sampling
–a specimen is picked up from a portion of mineralized outcrop/ore body
–samples are taken and analyzed to obtain a preliminary idea about the nature and grade of whole deposit and to know appreciate metal content
grab sampling
–suitable method for bedded, banded and vein type of deposits
–this method consists of cutting channels across the
face of exposed ore and collecting resulting chips, fragments and dust from each channel to make a sample
Channel/Groove/Trench Sampling
–used for hard or uniform ores where it is difficult to cut channels
–the samples are collected by taking a small series of chips of rocks on a regular grid pattern from the working face in regular intervals
–the blasted, broken material are sampled
–the shape of grid is adopted to the morphology and
structure of deposit.
–main advantage: its high productivity. (a lot of samples in faster rate)
Chip or Point Sampling
–involves cutting of pieces of ore and rock from exposed faces of ore and waste
–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
Face or Muck or Lump Sampling is common for what
laterites
face samples may be taken:
–by cutting grooves or channels of uniform width and depth across the face or sections of the face or
*involves the use of diamond cutters
*more systematic, and although ordinarily it is the one that is employed when accuracy is desired, pick sampling may sometimes be as accurate, or more so, depending on conditions.
–by picking off small pieces all over the face, more or less at random
Difference between trench sampling and mucking?
-almost the same, but mucking is exclusively cutting groves, need diamond cutters, but pwede ra sample pick for trenching
–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
–samples are taken by blasting down drift blocks or a
section in a stope or otherwise obtaining a sample of several tons to several hundred or even thousands of tons, either from trench, pit, channel or from the run-of-mine, where the entire lot is milled separately.
bulk sampling
includes ore and waste you get from underground, all materials extracted from mine
run-of-mine
processed stuff
run-of-mill
–collection and analysis of silt, sand, mud, clay in a stream or river bed, either dry or wet
–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
–more convenient for the determination of the deposits boundaries
–samples consist of the cuttings from drill holes
*may be intact core or chip samplings (u get before blasting) (before explosives, u get chips, then retrieval, u quarter to get representative sample (chips is aka cuttings)
drill hole sampling
2 types of errors in sampling
Random errors and Systematic errors
reasons for errors in sampling
- Improper spacing in samples
- Insufficient number of samples
- Improper location of samples
- Incorrect weighting of assay
- Failure to recognize ore, thus leaving it unsampled
- Improper chemical analysis
Common sampling patterns
regular, staggered, equidistant
–simplest grid design because 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
–not necessarily equal distance
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
considered the most reliable method for accurately determining the content of gold, silver, and platinum-group metals in ores or concentrates
fire assay
what platinum metals are not included in fire assay
osmium and ruthenium
what materials in fire assay
clay crucible, cupel
mixture of fluxes
lead oxide
reducing agent
mixture of fluxes example
silica and borax
lead oxide in fire assay
litharge
reducing agent in fire assay
flour mostly
smelting process, a concentrate in high temp condition to liberate (get out) target element from concentrate
pyrometallurgy
