Handbook of Corrosion Engineering Episode 2 Part 13 doc

1035 TABLE D.4 Pure Species Considered and Their Thermodynamic Data Species G 0 (298 K) , Jиmol Ϫ1 S 0 (298 K) , Jиmol Ϫ1 ABϫ 10 3 C ϫ 10 Ϫ5 C p , * Jиmol Ϫ1 иK Ϫ1 G 0 (333 K) ,† Jиmol Ϫ1 O 2 0 205 29.96 4.184 1.674 29.85 Ϫ7,234.04 H 2 0 131 27.28 3.263 0.502 28.82 Ϫ4,642.01 H 2 O Ϫ237,000 69.9 10.669 42.284 Ϫ6.903 18.54 Ϫ239,483 Al 0 28.325 20.67 12.38 0 24.79 Ϫ1,040.43 Al(OH) 3 Ϫ1,136,542 0 Ϫ1,136,542 Al 2 O 3 иH 2 O Ϫ1,825,500 96.86 120.8 35.14 0 132.51 Ϫ1,829,152 *Calculated with Eq. (D.46). †Calculated with Eq. (D.48). 0765162_AppD_Roberge 9/1/99 8:12 Page 1035 TABLE D.5 Soluble Species Considered and Their Thermodynamic Data Species G 0 (298 K) , S 0 ( 298 K) , S ˇ 0 (298 K) , ab C p ,* G 0 (333 K) ,† Jиmol Ϫ1 Jиmol Ϫ1 Jиmol Ϫ1 Jиmol Ϫ1 иK Ϫ1 Jиmol Ϫ1 H ϩ 00Ϫ20.9 0.065 Ϫ0.005 118.75 Ϫ234.9 OH Ϫ Ϫ157,277 41.888 20.968 Ϫ0.37 0.0055 Ϫ452.03 Ϫ157,849 Al 3ϩ Ϫ485,400 Ϫ321.75 Ϫ384.45 0.13 Ϫ0.00166 372.84 Ϫ474,876 Al(OH) 2ϩ Ϫ694,100 Ϫ142.26 Ϫ184.06 0.13 Ϫ0.00166 267.95 Ϫ689,651 Al(OH) 2 ϩ Ϫ900,000 205.35 184.43 0.13 Ϫ0.00166 75.06 Ϫ907,336 AlO 2 Ϫ Ϫ838,968 96.399 117.31 Ϫ0.37 0.0055 Ϫ284.94 Ϫ841,778 *Calculated with Eq. (D.47). †Calculated with Eq. (D.48). 1036 0765162_AppD_Roberge 9/1/99 8:12 Page 1036 G 0 (T 2 ) ϭ G 0 (T 1 ) Ϫ S 0 (T 1 ) [T 2 Ϫ T 1 ] Ϫ T 2 ͵ T 2 T 1 dT ϩ ͵ T 2 T 1 C p 0 dT (D.45) For pure substances (i.e., solids, liquids, and gases) the heat capaci- ty C p 0 is often expressed, as in Table D.4, as function of the absolute temperature: C p 0 ϭ A ϩ BT ϩ CT Ϫ2 (D.46) For ionic substances, one has to use another method, such as pro- posed by Criss and Cobble in 1964, 1 to obtain the heat capacity, provided the temperature does not rise above 200°C. The expression of the ionic capacity [Eq. (D.47)] makes use of absolute entropy values and the parameters a and b contained in Table D.4: C p 0 ϭ (4.186a ϩ bS 0 (298 K) ) (T 2 Ϫ 298.16) /ln ΂΃ (D.47) T 2 ᎏ 298.16 C p 0 ᎏ T Electrochemistry Basics 1037 TABLE D.6 Reactions Considered to Model an Aluminum-Air Corrosion Cell Water equilibria 2 e Ϫ ϩ 2 H ϩ ϭ H 2 4 e Ϫ ϩ O 2 ϩ 4 H ϩ ϭ 2 H 2 O OH Ϫ ϩ H ϩ ϭ H 2 O Equilibria involving aluminum metal 3 e Ϫ ϩ Al 3ϩ ϭ Al 3 e Ϫ ϩ Al(OH) 3 ϩ 3 H ϩ ϭ Al ϩ 3 H 2 O 6 e Ϫ ϩ Al 2 O 3 иH 2 O ϩ 6 H ϩ ϭ 2 Al ϩ 4 H 2 O 3 e Ϫ ϩ AlO 2 Ϫ ϩ 4 H ϩ ϭ Al ϩ 2 H 2 O 3 e Ϫ ϩ Al(OH) 2ϩ ϩ H ϩ ϭ Al ϩ H 2 O 3 e Ϫ ϩ Al(OH) 2 ϩ ϩ 2 H ϩ ϭ Al ϩ 2 H 2 O Equilibria involving solid forms of oxidized aluminum Al(OH) 3 ϩ H ϩ ϭ Al(OH) 2 ϩ ϩ H 2 O Al 2 O 3 иH 2 O ϩ 2 H ϩ ϭ 2 Al(OH) 2 ϩ Al(OH) 3 ϩ 2 H ϩ ϭ Al(OH) 2ϩ ϩ 2 H 2 O Al 2 O 3 иH 2 O ϩ 4 H ϩ ϭ 2 Al(OH) 2ϩ ϩ 2 H 2 O Al(OH) 3 ϩ 3 H ϩ ϭ 2 Al 3ϩ ϩ 4 H 2 O Al 2 O 3 иH 2 O ϩ 6 H ϩ ϭ Al 3ϩ ϩ 3 H 2 O Al(OH) 3 ϭ AlO 2 Ϫ ϩ H ϩ ϩ H 2 O Al 2 O 3 иH 2 O ϭ 2 AlO 2 Ϫ ϩ 2 H ϩ Equilibria involving only soluble forms of oxidized aluminum AlO 2 Ϫ ϩ 4 H ϩ ϭ Al 3ϩ ϩ 2 H 2 O 0765162_AppD_Roberge 9/1/99 8:12 Page 1037 By combining Eq. (D.46) or (D.47) with Eq. (D.45) one can obtain the free energy [Eq. (D.48)] at any given temperature by using the funda- mental data contained in Tables D.4 and D.5: G 0 (T) ϭ G 0 (298 K) ϩ (C p 0 Ϫ S 0 (298 K) ) (T 2 Ϫ 298.16) Ϫ T 2 ln ΂΃ C p 0 (D.48) Although these equations appear slightly overwhelming, they can be computed relatively simply with the use of a modern spreadsheet, where the data in Table D.4 could be imported with the functions in Eqs. (D.46) to (D.48) properly expressed. Calculate G for each species. For species O, the free energy of 1 mol can be obtained from G 0 with Eq. (D.49): G o(T) ϭ G o(T) 0 ϩ 2.303 RT log 10 a O (D.49) For x mol of species O the free energy is expressed by Eq. (D.50): xG 0(T) ϭ x (G O(T) 0 ϩ 2.303 RT log 10 a O ) (D.50) For pure substances such as solids, a O is equal to 1. For a gas, a O is equal to its partial pressure (p O ), as a fraction of 1 atmosphere. For sol- uble species, the activity of species O (a O ), is the product of the activi- ty coefficient of that species (␥ O ) with its molar concentration ([O]) (i.e., a O ϭ␥ O [O]). The activity coefficient of a chemical species in solution is close to 1 at infinite dilution when there is no interference from other chemical species. For most other situations the activity coefficient is a complex function that varies with the concentration of the species and with the concentration of other species in solution. For the sake of sim- plicity the activity coefficient will be assumed to be of value 1; hence Eq. (D.50) can be written as a function of [O]: xG O(T) ϭ x (G O(T) 0 ϩ 2.303 RT log 10 [O]) (D.51) Taking the global reaction fo the Al-O 2 system expressed in Eq. (D.44) and the G 0 values calculated for 60°C in Tables D.4 and D.5, one can obtain thermodynamic values for the products and reactants, as is done in Table D.7. Calculate cell ⌬G. The DG of a cell can be calculated by subtracting the G values of the reactants from the G values of the products in Table D.7. Keeping the example of the global reaction at 60°C in mind, one would obtain ⌬G ϭ G products ϪG reactants ϭϪ3,846,087Ϫ (Ϫ670,615) ϭϪ3,175,472 J T 2 ᎏ 298.16 1038 Appendix D 0765162_AppD_Roberge 9/1/99 8:12 Page 1038 Translate ⌬G into potential E ϭϭ ϭ2.74 V where n ϭ 12 because each Al gives off 3 e Ϫ [cf. Eq. (D.40)] and there are four Al in the global Eq. (D.44) representing the cell chemistry. Calculate the specific capacity (Ahиkg Ϫ1 ). The specific capacity relates the weight of active materials with the charge that can be produced, that is, a number of coulombs or ampere-hours (Ah). Because 1 A ϭ 1 Cиs Ϫ1 , 1 Ah ϭ 3600 C, and because 1 mole of e Ϫ ϭ 96,485 C (Faraday), 1 mole of e Ϫ ϭ 26.80 Ah. By considering the global expression of the cell chemistry expressed in Eq. (D.44), one can relate the weight of the active materials to a cer- tain energy and power. In the present case 12 moles of e Ϫ are produced by using 4 moles of Al 4 ϫ 26.98 gиmol Ϫ1 , or 107.92 g 4 moles of OH Ϫ as KOH 4 ϫ 56.11 gиmol Ϫ1 , or 224.44 g 3 moles of O 2 (as air) 0 g 3 moles of O 2 (compressed or cryogenic) 3 ϫ 32.00 g mol Ϫ1 , or 96.00 g Weight of active materials for the production of 12 moles of e Ϫ is then 332.36 g if running on free air and 428.36 g if running on compressed or cryogenic oxygen. The theoretical specific capacity is thus 26.80 ϫ 12/0.3324 ϭ 967.5 Ahиkg Ϫ1 if running on air and 26.80 ϫ 12/0.4284 ϭ 750.7 Ahиkg Ϫ1 if running on compressed or cryogenic oxygen. Calculate the energy density (Whиkg Ϫ1 ). The energy density can then be obtained by multiplying the specific capacity obtained from calculating the specific capacity with the thermodynamic voltage calculated when 3,188,818 ᎏᎏ (12 и 96,485) Ϫ⌬G ᎏ nF Electrochemistry Basics 1039 TABLE D.7 Calculated Free Energies for Species Involved in the Global Al-Air Reaction at 60°C G 0 (333 K) , 2.303RT Species x Jиmol Ϫ1 a o log 10 a O x G 0 (333 K) ∑G 0 (333 K) Reactants Al 4 Ϫ1040.43 1 0.00 Ϫ4161.72 OH Ϫ 4 Ϫ157,849 1 0.00 Ϫ631,396.00 O 2 3 Ϫ7,234.04 0.2 Ϫ4452.02 Ϫ35,058.17 Ϫ670,615.89 Products AlO 2 Ϫ 4 Ϫ841,778 0.1 Ϫ6369.39 Ϫ3,392,589.58 H 2 O2Ϫ239,483 1 0.00 Ϫ478,966.00 Ϫ3,846,087.21 0765162_AppD_Roberge 9/1/99 8:12 Page 1039 translating ⌬G into potentials: 2.74 ϫ 967.5 ϭ 2651 Whиkg Ϫ1 , or 2.651 kWhиkg Ϫ1 if running on air and, because the voltage for running on pure oxygen is slightly higher (i.e., 2.78 V), 2.78 ϫ 750.7 ϭ 2087 Whиkg Ϫ1 , or 2.087 kWhиkg Ϫ1 if running on compressed or cryogenic oxygen. Reference electrodes. The thermodynamic equilibrium of any other chemical or electrochemical reaction can be calculated in the same man- ner, provided the basic information is found. Table D.8 contains the chemical description of most reference electrodes used in laboratories and field units, and Tables D.9 and D.10, respectively, contain the ther- modynamic data associated with the solid and soluble chemical species making these electrodes. Table D.11 presents the results of the calcula- tions performed to obtain the potential of each electrode at 60°C (i.e., away from the 25°C standard temperature). D.2.6 Potential-pH diagrams Potential-pH (E-pH) diagrams, also called predominance or Pourbaix diagrams, have been adopted universally since their conception in the early 1950s. They have been repetitively proven to be an elegant way to represent the thermodynamic stability of chemical species in given aqueous environments. E-pH diagrams are typically plotted for vari- ous equilibria on normal cartesian coordinates with potential (E) as the ordinate (y-axis) and pH as the abscissa (x-axis). 2 Pourbaix diagrams are a convenient way of summarizing much ther- modynamic data, and they provide a useful means of predicting elec- trochemical and chemical processes that could potentially occur in certain conditions of pressure, temperature, and chemical makeup. These diagrams have been particularly fruitful in contributing to the understanding of corrosion reactions. Stability of water. Equation (D.52) describes the equilibrium between hydrogen ions and hydrogen gas in an aqueous environment:. 2H ϩ ϩ 2e Ϫ ϭ H 2 (D.52) which can be written as Eq. (D.53) in neutral or alkaline solutions: 2H 2 O ϩ 2e Ϫ ϭ H 2 ϩ 2OH Ϫ (D.53) Adding sufficient OH Ϫ to both sides of the reaction in Eq. (D.52) results in Eq. (D.53). At higher pH than neutral, Eq. (D.53) is a more appropriate representation. However, both representations signify the same reaction for which the thermodynamic behavior can be expressed by a Nernst Eq. (D.54): 1040 Appendix D 0765162_AppD_Roberge 9/1/99 8:12 Page 1040 TABLE D.8 Equilibrium Potential of the Main Reference Electrodes Used in Corrosion, at 25°C Name Equilibrium reaction Nernst Equation, V vs. S H E Potential, V vs. S H E T coefficient, mVиC Ϫ1 Hydrogen 2 H ϩ ϩ 2 e Ϫ ϭ H 2 (SHE) E 0 Ϫ 0.059 pH 0.00 Silver chloride AgCl ϩ e Ϫ ϭ Ag ϩ Cl Ϫ E 0 Ϫ 0.059 log 10 a ClϪ 0.2224 Ϫ0.6 0.1 M KCl 0.2881 1.0 M KCl 0.2224 Seawater ϳ 0.250 Calomel Hg 2 Cl 2 ϩ 2 e Ϫ ϭ 2 Hg ϩ 2 Cl Ϫ E 0 Ϫ 0.059 log 10 a Cl Ϫ 0.268 0.1 M KC1 0.3337 Ϫ0.06 1.0 M KC1 0.280 Ϫ0.24 (SCE) Saturated 0.241 Ϫ0.65 Mercurous sulfate Hg 2 SO 4 ϩ 2 e Ϫ ϭ 2 Hg ϩ SO 4 Ϫ2 E 0 Ϫ 0.0295 log 10 a SO4 2 Ϫ 0.6151 Mercuric oxide Hg O ϩ 2 e Ϫ ϩ 2 H ϩ ϭ Hg ϩ H 2 OE 0 Ϫ 0.059 pH 0.926 Copper sulfate Cu 2ϩ ϩ 2 e Ϫ ϭ Cu (sulfate solution) E 0 ϩ 0.0295 log 10 a Cu 2ϩ 0.340 Saturated 0.318 1041 0765162_AppD_Roberge 9/1/99 8:12 Page 1041 TABLE D.9 Data and Calculations of t the Free Energy and Potential of the Main Reference Electodes at 60°C (TemRef ϭ 25; TemC ϭ 60; TemA ϭ 333.16; T 2 Ϫ T 1 ϭ 35; ln(T 2 /T 1 ) ϭ 0.1109926) G 0 (298 K), S 0 (298 K), C p (333K),* G 0 T (333K), † Species Jиmol Ϫ1 Jиmol Ϫ1 AB CJиmol Ϫ1 иK Ϫ1 Jиmol Ϫ1 O 2 0 205 29.96 4.184 Ϫ1.674 29.85 Ϫ7234.04 H 2 0 131 27.28 3.263 0.502 28.8 Ϫ4642.01 H 2 O Ϫ237000 69.9 10.669 42.284 Ϫ6.903 18.5 Ϫ239483.00 Ag 0 42.55 21.297 8.535 1.506 25.5 Ϫ1539.69 Cu 0 33.2 22.635 6.276 24.7 Ϫ1210.91 Hg 0 76.02 26.94 0 0.795 27.7 Ϫ2715.41 AgC1 Ϫ109805 96.2 62.258 4.184 Ϫ11.297 53.5 Ϫ113277. Hg 2 C1 2 Ϫ210778 192.5 63.932 43.514 0 78.4 Ϫ217670. Hg 2 SO 4 Ϫ625880 200.66 131.96 132 Ϫ633164. HgO Ϫ58555 70.29 34.853 30.836 0 45.1 Ϫ61104.4 *Calculated with Eq. (D.46). †Calculated with Eq. (D.48). 1042 0765162_AppD_Roberge 9/1/99 8:12 Page 1042 1043 TABLE D.10 Thermodynamic Data of Soluble Species Associated with the Most Commonly Used Reference Electrodes G 0 (298K), S 0 (298K), S ˇ 0 (298K), Species Jиmol Ϫ1 Jиmol Ϫ1 Jиmol Ϫ1 abC p Eq.(D.47) Eq.(D.48) H ϩ 00Ϫ20.9 0.065 Ϫ0.005 118.7525 Ϫ234.927 Cu 2ϩ 65689 Ϫ207.2 Ϫ249.04 0.13 Ϫ0.00166 301.9618 72343.6 Cl Ϫ Ϫ131260 Ϫ12.6 8.32 Ϫ0.37 0.0055 Ϫ473.9694 Ϫ129881. SO 4 2Ϫ Ϫ744600 10.752 52.592 Ϫ0.37 0.0055 Ϫ397.1863 Ϫ744190. 0765162_AppD_Roberge 9/1/99 8:12 Page 1043 TABLE D.11 Calculations of the Equilibrium Associated with the Most Commonly Used Reference Electrodes at 60°C ΑG° reactants,* ΑG° products,* ⌬G° reaction, Potential, Name J и mol –1 J и mol –1 J и mol –1 V Hydrogen –470 –46,420 –4,172 0.0216 Silver chloride –113,277 –131,421 –18,144 0.1880 Calomel –217,670 –265,193 –47,523 0.2463 Mercurous sulfate –633,164 –749,621 –116,457 0.6035 Mercuric chloride –61,574 –242,199 –180,624 0.9360 Copper sulfate 72,344 –1,211 –73,555 0.3812 *Note: all species considered to be of activity = 1 1044 0765162_AppD_Roberge 9/1/99 8:12 Page 1044 [...]... (Continued) 07651 62_ AppE_Roberge TABLE E.1 1064 Chemical Composition Limits of Cast Aluminum Alloys A 020 10 A 020 20 A 020 30 A 020 40 A 020 60 A 020 80 A 021 30 A 022 20 A 022 40 A 023 80 A 024 00 A 024 20 A 024 30 A 024 90 A 029 50 A 029 60 A03050 A03080 A03190 A0 324 0 A0 328 0 A03 320 A03330 A03360 20 1.0 20 2.0 20 3.0 20 4.0 20 6.0 20 8.0 21 3.0 22 2.0 22 4.0 23 8.0 24 0.0 24 2.0 24 3.0 24 9.0 29 5.0 29 6.0 305.0 308.0 319.0 324 .0 328 .0 3 32. 0 333.0 336.0... 20 14 20 17 20 18 20 24 20 25 20 36 21 17 21 24 22 18 22 19 23 19 26 18 3003 3004 3005 3105 40 32 4043 4045 4047 Si 9/1/99 8:18 A91050 A91060 A91100 A91145 A91175 A9 120 0 A9 123 0 A9 123 5 A 9134 5 A 9135 0 A 920 11 A 920 14 A 920 17 A 920 18 A 920 24 A 920 25 A 920 36 A 921 17 A 921 24 A 922 18 A 922 19 A 923 19 A 926 18 A93003 A93004 A93005 A93105 A940 32 A94043 A94045 A94047 Chemical Composition Limits of Wrought Aluminum Alloys 07651 62_ AppE_Roberge... Rem 0. 02 0. 02 50–.7 0 .2 0 .2 0 .2 0.1 0.1 0 .2 0.15 Ni 50–1.0 1.0–1.4 1.4 2. 2 1.8 2. 5 1.8–3.0 50–1 .2 30–1 .2 0.1 0.15 0.1 Cr 35–.6 0 .25 0 .25 08–. 12 20–.30 0.1 Co 15–.55 6–.9 1 1.8 2. 2 2. 4 2. 7 0.3 10–.8 10– .20 25 –.35 05–.15 15–.40 20 –1.0 40–1 .2 20–.6 15–.45 50–1.5 6–1 .2 40–1 .2 Si 0 .2 0 .2 0 .2 0 .2 0 .2 0 .2 0 .2 0 .2 0 .2 40–.8 Be 1.60–1.79 1.80 2. 00 1.80 2. 00 15–.50 15–.50 15–.50 40–.7 20 –.6 20 –.40 Pb 0. 02 20–.6... 0.8–1 .2 0.40–0.8 0.45–0.9 0.40–0.8 2. 6–3.4 1.0–1.8 0.7–1.4 0.8–1.4 1 .2 1.8 1.3 2. 0 2. 0 2. 9 1.9 2. 6 0.10 2. 1 2. 9 2. 1 2. 9 2. 4–3.1 1.9 2. 6 Cr 0.10 0.03 0.04–0.35 0.04–0.14 0.18–0.35 0.06–0 .20 0. 12 0 .25 0.05 0.10–0 .22 0.04 0.18–0 .28 0.18–0 .28 0.18–0 .28 0.18–0 .25 Ni Zn 0 .25 0.10 1.6 2. 4 0 .25 0 .20 0.05 0 .20 6.8–8.0 4.0–5.0 4.5–5.5 4.0–5.0 5.0–6.0 4 .2 5 .2 7 .2 8 .2 5.7–6.7 0.8–1.3 5.1–6.1 5.1–6.1 6.3–7.3 5 .2 6 .2. .. 1.7 2. 3 1.7 2. 3 0.9–1 .2 0.10 0 .20 0.10 0.50–1.3 Zn 0.05 0.05 0.10 0.05 0.04 0.10 0.10 0.10 0.05 0.05 0.30 0 .25 0 .25 0 .25 0 .25 0 .25 0 .25 0 .25 0 .25 0 .25 0.10 0.10 0.10 0.10 0 .25 0 .25 0.40 0 .25 0.10 0.10 0 .20 Ti 0.03 0.03 0.03 0. 02 0.05 0.03 0.06 0.03 0.15 0.15 0.15 0.15 0.15 0.15 0. 02 0.10 0.10–0 .20 0.04–0.10 0.10 0.10 0 .20 0 .20 Page 10 62 1050 1060 1100 1145 1175 120 0 123 0 123 5 134 5 135 0 20 11 20 14 20 17 20 18... 0 .25 0 .20 0 .20 –0.30 0 .20 –0.30 0 .25 –0.50 0.30–0.40 0.50 0 .20 –0.30 0 .25 015 0.05 0.50 0.30 0.50 0.50 0.50 2. 0 2. 5 0.50 0 .25 Sn Ti 0 .25 0.50 0 .20 0 .25 0 .25 0 .20 0.10–0 .20 0 .20 015 0.10 0 .25 0.15 0.10 0.35 0.15 0.35 0.30 0.30 0 .20 0 .20 0 .20 0 .20 0.10–0 .20 0.15 0 .25 0 .25 0 .25 Page 1066 AA No 9/1/99 8:18 AA No 07651 62_ AppE_Roberge TABLE E .2 1066 07651 62_ AppE_Roberge TABLE E .2 Chemical Composition Limits of. .. 0.40 0.10 0.03 0.10 0.15–0.35 Ni Zn 0 .20 0 .20 0.10 0 .25 0 .25 0.10 0.10 0 .25 0 .25 0 .20 0 .25 0.05 0 .20 0.10 0 .25 0 .25 0.05 0 .25 0 .25 0.10 0 .20 0.05 0 .20 0.10 0 .25 0 .25 0.10 0 .25 0.10 0 .25 0 .25 0.10 0.10 0 .25 Ti 0.15 0.I5 0.15 0 .20 0.15 0.05 0.06–0 .20 0 .20 0 .20 Page 1063 4145 4343 4643 5005 5050 50 52 5056 5083 5086 5154 5183 525 2 525 4 5356 5454 5456 5457 5554 5556 56 52 5654 5657 6003 6005 6009 6010 6053... 0 .25 0 .20 –0.40 0.10 0.10 0.10 1.0 2. 5 0.8 1.0 0.30–0.7 1.7 2. 3 1.9 2. 3 1.5 0.10 0.35 0.05 2. 5–3.5 0.35 0.50 0.35 1.0 1.0 1.0 1.5 1.0 1.0 0.35 0.35 0 .25 0.35 0.35 0.30 0 .25 0.50 0.50 2. 0–3.0 0.05 0.05 Ti 0.15–0.35 0.15–0.35 0.15–0 .25 0.15–0.30 0.15–0.30 0 .25 0 .25 0 .25 0.35 0 .25 0 .20 0 .25 0.06–0 .20 0. 02 0.35 0 .25 0 .25 0 .25 0 .25 0 .25 0 .20 0 .25 0 .25 0 .25 0 .25 Page 1065 AA No 9/1/99 8:18 AA No 07651 62_ AppE_Roberge... C15 720 C15 725 C15760 C15815 Cu 99. 62 99. 52 99.43 98.77 97. 82 Ag As Sb 0.054 0.0 12 0.003 P Te 0. 025 0.075 0.0 02 015–.040 15–.50 005–. 020 004–.0 12 010–.030 004–. 020 001–.010 0 02 .005 027 –.10 Al 13 .17 18– .22 23 – .27 58–. 62 13 .17 005–.05 40–.7 30–.7 40–.7 003–0. 023 040–.080 Fe Pb 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 O 12 .19 16– .24 20 – .28 52 .59 0.19 B 1 .2 1.8 Other 050Ni, 003Bi, 004Pb 02Pb,... 0.7–1.3 0 .20 –0.6 0 .20 –0.50 0.35 0.35 0.10 0.10 0 .25 0.10 0 .25 0. 12 0.7 Si ϩ Fe 0.40–0.50 0.15 0 .20 0.40 0.50 0.10 0.50 0.50 0.50 0.7 0.50 0.15 0.8 0.40 0.40 0.10 0. 12 0.40 0. 12 0.35 0.15 0 .20 0.10 0.10 0.15–0.40 0.10 0 .20 0.15–0.40 1.6 2. 6 0.10 0.05 0.45–1.0 0 .25 0.50–0.9 1 .2 1.9 2. 0 2. 6 0.10 1 .2 2. 0 1 .2 2. 0 1.6 2. 4 1 .2 1.9 0. 12 Mn 0.10 0.03 0.15 0.40–0.8 0.05 0.10 0 .20 0 .20 –0.7 0.05 0.03 0.10 0.03 0 .20 0.10 . 3 .26 3 0.5 02 28.8 Ϫ46 42. 01 H 2 O 23 7000 69.9 10.669 42. 284 Ϫ6.903 18.5 23 9483.00 Ag 0 42. 55 21 .29 7 8.535 1.506 25 .5 Ϫ1539.69 Cu 0 33 .2 22. 635 6 .27 6 24 .7 Ϫ 121 0.91 Hg 0 76. 02 26.94 0 0.795 27 .7. Ϫ4,6 42. 01 H 2 O 23 7,000 69.9 10.669 42. 284 Ϫ6.903 18.54 23 9,483 Al 0 28 . 325 20 .67 12. 38 0 24 .79 Ϫ1,040.43 Al(OH) 3 Ϫ1 ,136 ,5 42 0 Ϫ1 ,136 ,5 42 Al 2 O 3 иH 2 O Ϫ1, 825 ,500 96.86 120 .8 35.14 0 1 32. 51 Ϫ1, 829 ,1 52 *Calculated. 0.795 27 .7 27 15.41 AgC1 Ϫ109805 96 .2 62. 258 4.184 Ϫ11 .29 7 53.5 Ϫ11 327 7. Hg 2 C1 2 21 0778 1 92. 5 63.9 32 43.514 0 78.4 21 7670. Hg 2 SO 4 Ϫ 625 880 20 0.66 131 .96 1 32 Ϫ633164. HgO Ϫ58555 70 .29 34.853