Grains size distribution

The grain size distribution for instance affects the adsorption capacity of clay, the viscosity of a casting slip, the plasticity of the raw material mixture and the reaction speed of the sintering process. Some methods to determine the grain size distribution are the simple sieving analysis which was elaborately discussed in chapter 9 and the more sophisticated methods  

A well-known device here is the Sedigraph in which a cuvette containing a suspension moves in relation to an X-ray beam (figure 13.4). 

The Sedigraph is connected to a plotter which can represent the grain size distribution in several ways, for example as in figure 13.5. 

As far as figure 13.5 is concerned, it should be noted that the percentage along the y axis only applies to the cumulative curve. 

The Coulter Counter contains a capillary through which a suspension is pumped. The electrical resistance of the liquid column is measured and depends on the resistance of the liquid medium, the resistance of the solid phase and the proportion of solid material in the suspension. From the size of the change in electrical resistance, certain conclusion can be drawn about the dimension of the particles in a certain fraction. 

2 Fill material properties 11.3.2.1 Grain size distribution 

Specifications are normally designed to ensure a well-mixed fill without unacceptable segregation of fines. This allows the fulfilment of density requirements whilst reducing the risk of liquefaction and/or intolerable deformations and settlements. Specifications for the granular composition of hydraulic fill generally comprise  

Methods and tools available for monitoring and testing the granular composition of fill material are presented in Appendix B. 

---

Grain size distributions for sediments and soils are used to determine the amount of sand, silt, and clay present in a sample. For example, a grain size of 2 mm serves as a boundary between gravel and sand. Grain size boundaries for sand-silt and silt-clay are given as 1/16 mm and 1/256 mm, respectively. 

Particle-SiZe Distribution. Particle-size specifications for sugar are not usually a part of the legislated standards, but they are of concern to commercial users and suppHers and are often specified in contracts. Grain-size distribution is determined by using a series of sieves, either hand-sieved or machine-sieved (13). 

X-RAY FLUORESCENCE INTENSITY ELEMENTS OE MULTICOMPONENT POWDER MATERIAL WITH CONTINUOUS GRAIN SIZE DISTRIBUTION OE COMPONENTS... 

Other ways that have been suggested to improve tire bed conductivity are to use a bi-modal grain size distribution to increase the packing density, or to add... 

T. D. Burchell, A. P. G. Rose and M. O. Tucker. The influence of grain size distribution on a fracture criterion for graphites. In Proc. 17th Biennial Conf on Carbon, Lexington KY, USA. Pub. American Carbon Society, 1985, pp.346 347. 

Mineral composition, permeability, and porosity, grain-size distribution, in-situ density, moisture content... 

The actual requirements for the sand in slow filtration are chemical in nature. Purity and the absence of undesirable matters are more important than grain-size distribution in the filtration process. On the other hand, the performance of rapid filters requires sands with quite a higher precise grain size. In the case of rapid filtration, the need for hydraulic performances is greater than in slow nitration. This means that the grain-size distribution of the medium is of prime concern in the latter case. 

This depends very largely on the composition of the body and the temperature to which it is fired. The addition of a clay grog will normally reduce the tensile strength but the degree of reduction depends on the proportion used, the grain-size distribution of the grog, and the particle shape. The... 

The grain size distribution of spent foundry sand is very uniform, with approximately 85 to 95% of the material between 0.6mm and 0.15mm (No. 30 and No. 100) sieve sizes. Five to twelve percent of foundry sand can be expected to be smaller than 0.075 mm (No. 200 sieve). The particle shape is typically subangular to round. Spent foundry sand gradations are too fine to satisfy the fine aggregate standard specified in specification ASTM C33 Standard Specification for Concrete Aggregates. 

The main parameters that affect the cost-effectiveness of soil washing include the physicochemical parameters of the soil (grain size distribution, cation exchange capacity, percentage of silt, clay, or organic matter), and the type and concentration of contaminants. 

Pierard C, Budzinski H, Garrigues P (1996) Grain-size distribution of polychlorobiphenyls in coastal sediments. Environ Sci Technol 30(9) 2776-2783... 

The plant is used to produce two chemically different EPS -types A and B in five grain size fractions each from raw materials FI, F2, F3. The polymerization reactions exhibit a selectivity of less than 100% with respect to the grain size fractions Besides one main fraction, they yield significant amounts of the other four fractions as by-products. The production processes are defined by recipes which specify the EPS-type (A or B) and the grain size distribution. For each EPS-type, five recipes are available with the grain size distributions shown in Figure 7.2 (bottom). The recipes exhibit the same structure as shown in Figure 7.2 (top) in state-task-network-representation (states in circles, tasks in squares). They differ in the parameters, e.g., the amounts of raw materials, and in the temperature profiles of the polymerization reactions. 

The grain size distribution can also be changed by the use of different grinding equipment, e. g. by a series of different mills. 

Reetz and Haase [5.2] used different freezing rates to freeze Zr02, and found slow freezing of this product to result in better technological qualities, e. g. free-flow and sinter ability than quick freezing. On the other hand, complex Zn- solutions can only be frozen quickly to arrive at a product homogeneous in chemical structure and grain size distribution. 

In order to prepare standard mineral mixtures, pyrite (Py), pyrrhotite (Po), chalcopyrite (Cp), sphalerite (Sp), siderite (Sid), dolomite (Dol), calcite (Cal) and quartz (Qz) were acquired as pure mineral samples through a specialized distributor (Minerobec, Canada). These 8 pure minerals were further cleaned under a binocular microscope and separately crushed to reach 95% under 150pm (typical tailings grain size distribution e.g. Aubertin et al. 2002). Each pure mineral powder was characterized thereafter with a series of chemical and mineralogical techniques. More details can be found in Bouzahzah et al. (2008). The relative density of each mineral specimen were measured with an He pycnometer and are... 

The most important features of these ores are (a) the valuable constituents occur as minerals of high density, (b) they do not have middlings and (c) the grain-size distribution falls in a region where a gravity technique can be adopted successfully. 

Geologic and hydrogeologic conditions (grain size distribution, packing density, hydraulic conductivity, etc.) ... 

Grain-size distribution in common marine sediments and in various sediment sources. Source From Gross, M. G. (1987). Oceanography A View of the Earth, 4th ed. Prentice Haii, inc., p. 81. 

---