Wyniki wyszukiwania - BazTech

1

A geometric approach to evaluating the results of Polish copper ores beneficiation

Foszcz D., Niedoba T., Tumidajski T.

Gospodarka Surowcami Mineralnymi

|

2018

|

T. 34, z. 2

55--66

EN

The separation or beneficiation processes are conducted in many devices and concern many various types of minerals and raw materials. The aim of conducting these processes is always to achieve the best possible results allowing as much of the useful component as possible to be obtained by maintaining reasonable costs of the process. Therefore, it is important to have the possibility to monitor the process effects and to have efficient tools to evaluate the course of it. Generally, the ore’s ability to partition into concentrate and tailings is called its efficiency, upgradeability etc. It can be said that there is no unambiguous measure of upgradeability and there are many factors in use which enable to evaluate it qualitatively. Among them are such commonly known parameters as: recovery, losses, yield, upgrading ratio and many others. They are based on three principal parameters that is the average content of the useful component α, the contents of this component in concentrate β and the contents of this component in tailings ϑ. For a given ore (assuming that α = constant), the multi-product separation results can be treated as points of a trajectory located on the surface of factor w in a three dimensional space (β, ϑ, w). The course of the trajectory depends on the ore petrographic and mineralogical properties preparation for the process. For these reasons, searching for optimal (potential) possibilities of the ore is relative, which is presented in the example of Halbich, Fuerstenau and Madej upgrading curves. Such curves are efficient tools to evaluate the course of a separation (beneficiation) process and each of their types allow the effects to be shown in different perspective. Apart from this, they allow also the optimal feed conditions to conduct a certain process with aim of achieving the expected results to be found. Furthermore, the effect of the ore preparation on the flotation results, on the sum of recoveries of the useful component in concentrate and residual recovery in tailings is presented in the paper. The results indicated that any additional contamination of concentrate should be taken into account during the organization of the flotation process. In this way, the results of fractionated flotation have much valuable information to establish the course of the process.

PL

Procesy rozdziału czy wzbogacania prowadzone są za pomocą wielu typów urządzeń i dotyczą wielu różnorodnych minerałów i surowców. Celem prowadzenia tych procesów jest zawsze uzyskanie możliwie najlepszych wyników, które umożliwią uzysk tak dużej ilości składnika użytecznego, jak tylko jest to możliwe, przy utrzymaniu rozsądnych kosztów prowadzenia procesu. Zatem istotne jest, aby istniała możliwość monitorowania efektów procesu oraz aby dysponować efektywnymi narzędziami oceny jego przebiegu. Ogólnie, zdolność rudy do rozdziału na produkty, którymi są koncentrat i odpad nazywa się jego wzbogacalnością. Można powiedzieć, że nie istnieje jedna uniwersalna miara wzbogacalności, a w użyciu jest wiele wskaźników, które umożliwiają jej jakościową ocenę. Między nimi są tak powszechnie znane wskaźniki, jak uzysk, straty, wychód, wskaźnik wzbogacania oraz wiele innych. Bazują one na trzech głównych parametrach, którymi są średnia zawartość składnika użytecznego w nadawie α, zawartość tego składnika w koncentracie β oraz zawartość tego składnika w odpadzie ϑ. Dla konkretnej rudy (przy przyjęciu, że α = constant) wyniki rozdziału na wiele produktów można traktować jako punkty na trajektorii, zlokalizowane na powierzchni wskaźnika w trójwymiarowej przestrzeni (β, ϑ, w). Przebieg trajektorii zależy od przygotowania właściwości petrograficznych i mineralogicznych rudy do procesu. Z tych powodów poszukiwanie optymalnych (potencjalnych) możliwości wzbogacania rudy jest relatywne, co można zaobserwować na przykładzie krzywych wzbogacalności Halbicha, Fuerstenau’a i Madeja. Takie krzywe są efektywnymi narzędziami oceny przebiegu procesu rozdziału (wzbogacania) i każdy z ich typów pozwala na przedstawienie efektów z innej perspektywy. Ponadto, pozwalają one również na znalezienie optymalnych warunków nadawy do prowadzenia danego procesu z celem osiągnięcia oczekiwanych wyników. Co więcej, wpływ przygotowania rudy na wyniki flotacji, sumę uzysków składnika użytecznego w koncentracie oraz uzysk reszt w odpadach zostały zaprezentowane w artykule.

2

Simultaneous optimization of flotation column performance using genetic evolutionary algorithm

Nakhaei F., Irannajad M., Yousefikhoshbakht M.

Physicochemical Problems of Mineral Processing

|

2016

|

Vol. 52, iss. 2

874--893

EN

Column flotation is a multivariable process. Its optimization guarantees the metallurgical yield of the process, expressed by the grade and recovery of the concentrate. The present work aimed at applying genetic algorithms (GAs) to optimize a pilot column flotation process which is characterized by being difficult to be optimized via conventional methods. A non-linear mathematical model was used to describe the dynamic behavior of the multivariable process. The solution of the optimization problem using conventional algorithms does not always lead to convergence because of the high dimensionality and non-linearity of the model. In order to deal with this process, the use of a genetic evolutionary algorithm is justified. In this way, GA was coupled with the multivariate non-linear regression (MNLR) of the column flotation metallurgical performance as a fitting function in order to optimize the column flotation process. Then, this kind of intelligent approach was verified by using mineral processing approaches such as Halbich’s upgrading curve. The aim of the optimization through GAs was searching for the process inputs that maximize the productivity of copper in the Sarcheshmeh pilot plant. In this case, the simulation optimization problem was defined as finding the best values for the froth height, chemical reagent dosage, wash water, air flow rate, air holdup, and Cu grade in rougher and column feed streams. The results indicated that GA was a robust and powerful search method to find the best values of the flotation column model parameters that lead to more reliable simulation predictions at a reasonable time. Based on the grade–recovery Halbich upgrading curve, the MNLR model coupled with GA can be used for determination of the flotation optimum conditions.

3

Accuracy of separation parameters resulting from errors of chemical analysis, experimental results and data approximation

Foszcz D., Duchnowska M., Niedoba T., Tumidajski T.

Physicochemical Problems of Mineral Processing

|

2016

|

Vol. 52, iss. 1

98--111

EN

Accuracy of determination of different separation parameters and selectivity indicators depends on the error of chemical analysis of feed and separation products as well as experimental and approximation errors. In this paper different selectivity parameters were considered which formulae was based on the content of useful component in the feed, concentrate and tailing. It was shown that the impact of chemical analysis on the selectivity parameters was small and the error determined by means of partial derivative approach for a copper ore upgraded by flotation was negligible. Also experimental errors were found to be insignificant. The largest errors occurred for approximation of the upgrading data with inadequately selected selectivity indicators.

4

Transformation of equation y=a(100-x)/(a-x) for approximation of separation results plotted as Fuerstenau's upgrading curve for application in other upgrading curves

Duchnowska M., Drzymała J.

Physicochemical Problems of Mineral Processing

|

2011

|

Vol. 47

123-130

EN

Equation y= a(100-x)/(a-x), frequently used for approximation of separation results plotted in the Fuerstenau upgrading curve, relating recovery of a selected component of the feed in the concentrate (x = ε) with recovery of another component in the tailing (y = εr), can be transformed into one-fitting parameter equation suitable for other upgrading curves. The mathematical formulas for the so-called Luszczkiewicz, Mayer, Henry, Stepinski, Hall, and Halbich separation upgrading curves were derived and presented.