Rappresentazione di anima e di corpo

Digitoitu 17. 9. 2008.

[Tripartita op. 5]

Soitinnus: orkesteri.

[Tripartita] : [osat 2. Adagio ja 1. Scherzo]

Soitinnus: orkesteri.

Dia

Digitoitu 15. 10. 2007.

Chelating Adsorbents in Purification of Hydrometallurgical Solutions

In this thesis, equilibrium and dynamic sorption properties of weakly basic chelating adsorbents were studied to explain removal of copper, nickel from a concentrated zinc sulfate solution in a hydrometallurgical process. Silica-supported chelating composites containing either branched poly(ethyleneimine) (BPEI) or 2-(aminomethyl)pyridine (AMP) as a functional group were used. The adsorbents are commercially available from Purity Systems Inc, USA as WP-1® and CuWRAM®, respectively. The fundamental interactions between the adsorbents, sulfuric acid and metal sulfates were studied in detail and the results were used to find the best conditions for removal of copper and nickel from an authentic ZnSO4 process solution. In particular, the effect of acid concentration and temperature on the separation efficiency was considered. Both experimental and modeling aspectswere covered in all cases. Metal sorption is considerably affected by the chemical properties of the studied adsorbents and by the separation conditions. In the case of WP-1, acid affinity is so high that column separation of copper, nickel and zinc has to be done using the adsorbent in base-form. On the other hand, the basicity of CuWRAM is significantly lower and protonated adsorbent can be used. Increasing temperature decreases the basicity and the metals affinity of both adsorbents, but the uptake capacities remain practically unchanged. Moreover, increasing temperature substantially enhances intra-particle mass transport and decreases viscosities thus allowing significantly higher feed flow rates in the fixed-bed separation. The copper selectivity of both adsorbents is very high even in the presence of a 250-fold excess of zinc. However, because of the basicity of WP-1, metal precipitation is a serious problem and therefore only CuWRAM is suitable for the practical industrial application. The optimum temperature for copper removal appears to be around 60 oC and an alternative solution purification method is proposed. The Ni/Zn selectivity of both WP-1 and CuWRAM is insufficient for removal of the very small amounts of nickel present in the concentrated ZnSO4 solution.

Aineettoman pääoman ja organisaatio-osaamisen hyödyntäminen

Tutkimuksen tarkoitus: Tutkimuksen tavoitteena on selvittää miten Tuomi Yhtiöt Oy:n aineetonpääoma ja organisaatio-osaaminen vaikuttavat yrityksen menestymiseen taantuman aikana 2008- 2009. Tutkimus ajoittuu maailman talouden kulminaatiopisteeseen, jossa voidaan tarkastella sekä mikro- että makrotalouden tunnuksilla miten yritys on menestynyt ja toiminut ajanjakson aikana. Tutkimuksen teoria on liiketaloustieteiden tutkimusmenetelmien mukaista, ja perustoiminnoiltaan normatiivista sekä empiiristä ongelmanratkaisua. Työssä käytettään laaja-alaisesti yrityksen faktatietoja, sekä aineettoman pääoman mittaamiseen tehtyä mittaristoa joka on rakennettu tutkimusta varten. Tuloksina saadaan yrityksen kannalta keskeiset organisaatio- ja aineettoman pääoman tunnusluvut, joita vertaillaan johtamisjärjestelmän tunnuslukuihin. Tutkimuksen yhteydessä on löydetty uusi asiakashallintamalli jolle ei ole saatavilla valmista sovellutusta. Yhteenvetona voidaan osoittaa yrityksen heikkoudet sekä menestyminentarkasteluajanjaksolla ja todistaa näiden yhteys kokonaisuuteen