Introduction part 2 Flashcards
the method or operation of taking the small amount of material from the bulk.
Sampling
be defined as the operation of removing a part, convenient in quantity for analysis, from a whole which is much greater, in such a way that the proportion and distribution of the quality to be tested are the same in both the sample and the whole.
Sampling
sa sampling
At first, a large quantity sample is collected from a lot, known as
primary sample or gross sample
Reduction of this reduced sample to a quantity necessary for analysis, known as final sample or test sample, is called (1). It is the process of reducing the quantity by (2)
sample preparation
splitting
The two methods used to obtain a gross sample are
Random sampling and Systematic sampling
The gross sample is reduced to a quantity that can be handled with ease by alternate shoveling or fractional shoveling in stages depending upon the quantity of the gross sample. It is essential that the gross sample be thoroughly mixed before reduction in order to obtain a representative sub-sample or laboratory sample. Such reduced samples are called (1) and (2) sample depending upon the number of stages used
secondary sample
ternary
Sample preparation is done by (1) and (2)
Coning and Quartering
A common falling ore sampling device is the (1)
Vezin Sampler
Sampling devices called (1) are used for pulp sampling in pipes
poppet valves
These are typically used in pipes where the flow is upward. In a process plant, or mine, the preferred method of obtaining a sample, is from a moving stream, such as a (1), a (2), or perhaps from a (3) that a stream of ore flows through
Conveyor Belt, slurry pipe line, chute
The material collected each time is called an
Increment
The ____, which is defined as the ratio of the weight of the sample taken by the sampling system to the weight of the lot from which that sample is taken, is the most important indicator of the performance of the sampling system.
SAmpling Ratio
Size of the particle is an important consideration in Mineral Beneficiation because of the following main reasons:
2 ka reason
- Energy consumed for reducing the size of the particles depends on size.
- Size of the particles determines the type of size reduction equipment, beneficiation equipment and other equipment to be employed.
____ or ____of an irregular particle is defined as the diameter of a spherical particle which behaves similar to an irregular particle under specified conditions
Equivalent size or Equivalent Diameter
____ is defined as a diameter of a spherical particle having the same surface area as the irregular particle
Surface Diameter
____ is defined as the diameter of a spherical particle having the same volume as the irregular particle
Volume Diameter
____ are used in the mineral industry to measure the size of the small and the fine particles, usually down to 74 microns.
3 words
Standard test Sieves
____ is a circular shell of brass having an 8 inch diameter and being about 2 inch high
Test Sieves
____ is made of wire, woven to produce nominally uniform cloth apertures (openings). The ____ is placed in the bottom of the shell so that material can be held on the sieve
Sieve Cloth
____ (or Opening) is a distance between two parallel wires.
Aperture
____is the number of apertures per linear inch. Sieves are designated by ____
Mesh Number
____ is the size of an aperture i.e. the distance between two parallel wires. As mesh number increases, ____ decreases.
Mesh Size
____ is the list of successive sieve sizes used in any laboratory, taken in order from coarsest to finest.
Sieve Scale
____ is the sieve scale adopted for size analyses and general testing work to facilitate the interchangeability of results and data. In this ____, the sizes of successive sieves in series form a geometric progression.
Standard Sieve Scale
the reference point is ____ microns, which is the aperture of a ____ mesh woven wire sieve
74
200
The ratio of the successive sizes of the sieves in the standard sieve scale is ____, which means that the area of the opening of any sieve in the series is ____ that of the sieve just below it and ____ of the area of the sieve above it in the series.
√2
twice
one half
____ - It is a method of size analysis. It is performed to determine the percentage weight of closely sized fraction by allowing the sample of material to pass through a series of test sieves.
Sieve Analysis
The ____ is considered more effective as it allows the particles to present in all possible orientations on to the sieve surface
Hand Sieving Method
However, ____ is preferred for routine analysis as hand sieving is long and tedious
Machine Sieving
____ and ____ are the two principal machines used in a laboratory for sieve analysis.
Table Model Sieve Shaker
Ro-Tap Sieve Shaker
Sieving is generally done ____. ____ is used when the material is in the form of slurry. When little moisture is present, a combination of wet and dry sieving is performed by initially ____
dry
wet sieving
adding water
____ is accomplished in stock piles, bins, tanks and ponds
Storage
____ is essentially a conveying operation in which the distance traveled is short and in which close regulation of the rate of passage is required.
Feeding
____ ore can be carried out to facilitate sorting by removing obscuring dirt from the surfaces of the ore particles.
Washing of Run-of-ore mine
____ - are steeply inclined troughs of rectangular sections for the gravity transport of dry solids
Chutes
the most versatile and widely used type, consists of an endless belt running around head and tail pulleys and resting on various kinds of idlers at intervals along both its upper and return runs.
Belt Conveyor
The following are the main purposes of ore storage:
1 To receive ore____ and deliver it smoothly.
2 To accumulate ____ for intermittent disposal.
3 To maintain an ____ of ore for treatment.
4 To smooth out ____ in working (surge storage).
5 To facilitate ____ of dissimilar minerals.
- Intermittently
- Mill Products
- Adequate tonnage
- irregularities
- Balanced Blending
____ are necessary whenever it is desired to deliver a uniform stream of dry or moist ore.
Feeders
