| 61. |
- Forssberg, Eric, et al.
(författare)
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Liberation modelling of base metal ores in autogenous grinding
- 1985
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Ingår i: Scandinavian journal of metallurgy. - 0371-0459 .- 1600-0692. ; 14:1, s. 9-17
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Tidskriftsartikel (refereegranskat)abstract
- According to a mathematical model, each mineral has its own liberation-energy characteristic curve which can be plotted. The relations between liberation, mill speed and charge volume are also presented.
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| 62. |
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| 63. |
- Forssberg, Eric, et al.
(författare)
-
Shape and liberation studies on grinding products from autogenous and conventional mill using an automatic image analyser
- 1985
-
Ingår i: Scandinavian journal of metallurgy. - 0371-0459 .- 1600-0692. ; 14:6, s. 283-288
-
Tidskriftsartikel (refereegranskat)abstract
- Samples were collected from the Stekenjokk and Malmberget concentrators, operated by Boliden Mineral AB and Luossavaara-Kiirunavaara AB respectively. The Stekenjokk ore consists of massive pyrite with disseminated chalcopyrite and sphalerite; it assays 1. 4 % Cu and 3. 2 % Zn. The Malmberget ore mainly contains magnetite with a coarse-crystalline structure; run-of-mine ore assays are about 40 % Fe and 0. 6 % P. Using an automatic image analyzer, it appears that fully autogenous grinding down to flotation fineness results in better liberation and particle shape for flotation than is obtained with a combination of primary autogenous and ball mill grinding. Fully autogenous grinding also creates smoother particle surfaces.
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| 64. |
- Forssberg, Eric, et al.
(författare)
-
Shape and surface properties of the particles liberated by autogenous grinding
- 1985
-
Ingår i: Scandinavian journal of metallurgy. - 0371-0459 .- 1600-0692. ; 14:1, s. 25-32
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Tidskriftsartikel (refereegranskat)abstract
- Autogenous grinding produces rounded particles with higher degrees of liberation and equiaxiality and lower roughness. These properties result in a higher grade concentrate and better recovery. Autogenous grinding is consequently more economical.
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| 65. |
- Fransson, Lennart, et al.
(författare)
-
Brash ice shear properties : laboratory tests
- 1985
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Ingår i: POAC 85. - Hørsholm : Dansk hydraulisk institut. - 8798195018
-
Konferensbidrag (refereegranskat)abstract
- According to earlier studies of brash ice covered channels and problems connected with winter navigation laboratory tests have been performed, treating brash ice as a Mohr-Coulomb material cohesion and shear properties have been studied. A shear box, 0. 5 multiplied by 0. 5 m, equipped with a water bag for normal loading, was used. The force required to shear the rubble was determined as a function of normal force, shear rate and ice piece thickness. The test results are analyzed and presented. The results are also compared with results from other studies and the applicability is discussed
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| 66. |
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| 67. |
- Fransson, Lennart
(författare)
-
Load bearing capacity of an ice cover subjected to concentrated loads
- 1985
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Ingår i: Proceedings of the Fourth International Offshore Mechanics and Arctic Engineering Symposium. - New York : American Society of Mechanical Engineers. ; , s. 170-176
-
Konferensbidrag (refereegranskat)abstract
- This work presents theoretical and field investigations of the bearing capacity of floating ice covers subjected to concentrated loads. The field tests were performed in the Gulf of Bothnia on columnar sea-ice with low salinity and with a thickness of 0. 4-0. 8 m. Thick plates with vertical anisotropy such as the tested ice covers have shown large local shear deformations and nonlinear creep. An empirical model is presented for the prediction of deflections based on curve fitting where these facts are taken into account. A modified strain-energy criteria or a local puncing are assumed to govern the failure. The failure load as a function of ice thickness and loading rate is plotted for a certain ice type. The bearing capacity of reinforced ice covers is compared with natural ice and the effect of different reinforcements such as wooden bars is discussed
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| 68. |
- Fredriksson, Sverker, et al.
(författare)
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New ideas on the proton-neutron differences in deep inelastic structure functions
- 1985
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 162:4-6, s. 373-378
-
Tidskriftsartikel (refereegranskat)abstract
- It is shown how future data from deep inelastic scattering of charged leptons on protons and neutrons can be used to discriminate between the two main possible scale-breaking QCD effects - perturbative gluon processes and non-perturbative diquark formation. Current data from the Stanford Linear Accelerator Center and from CERN on the structure function combinations Fp2-Fn2, Fn2/Fp2 and σL/σT are in line with both the Stockholm diquark model and perturbative QCD, considering the low statistics as well as the possibility of a substantial normalisation error between the two data sets. This calls for a new high-statistics experiment on a deuterium target before any definite conclusions can be made.
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| 69. |
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| 70. |
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