I am using a longtable that expands up to 3 pages in Landscape mode. I have used makecell, to insert linebreaks and vertically and horizontaly align the contents in cells. I want to enter footnote in the long table and for that I am using threeparttablex package. The problem is when I run below code the longtable stays in single page and overflows it. Please help me behave my longtable in regular way and expand to 3 pages instead of overflowing in a single page. Here is my code:
\documentclass[12pt,hidelinks]{scrreprt}
\usepackage{setspace,url,hyperref,array,booktabs,siunitx,textgreek,graphicx,subcaption, lscape, longtable, vcell, pdflscape, mlmodern,tabularx,makecell,threeparttablex}
\usepackage[version=4]{mhchem}
\renewcommand{\cellalign}{tl}
\renewcommand{\theadalign}{br}
\begin{document}
\begin{landscape}
\begin{threeparttable}
\begin{TableNotes}
\item [a] abcd is fun
\end{TableNotes}
\begin{longtable}{llllp{3.3 cm}}
\caption{Summary of metal recovery from spent refining catalysts using hydrometallurgy} \label{hydrometalcompilation} \\[1 ex]
\toprule
Methods used &
Catalyst &
Optimum conditions &
Result, \% &
Reference \\* \midrule
\endhead
%
\bottomrule
\endfoot
\insertTableNotes
\endlastfoot
%
\makecell{Roasting - \\ acid leaching - \\ solvent extraction} &
\makecell{Spent \\ hydrogenation \\ catalyst} &
\makecell{Roasting:\\ 400 \textsuperscript{o}C, 2 h\\ Leaching:\\ 1 M \ce{H2SO4}, 75 \textsuperscript{o}C, 20 min, \\ S/L = 1/10\\ Mo/V coextraction:\\ 0.3 M TOA + 0.7 M C272, \\ pH = 1\\ Ni extraction:\\ 50\% (v/v) HBL110, pH = 2} &
\makecell{Leaching efficiency\\ Al = 22.16,\\ Ni = 99.44,\\ Mo = 98.59,\\ V = 100\\ Final products\\ \ce{NiSO4}, \ce{Na2MoO4},\\ \ce{VOSO4} } &
CHEN2022 \\
\makecell{Vacuum pyrolysis - \\ roasting - \\ acid leaching} &
\makecell{Spent \\ hydroprocessing \\ catalyst} &
\makecell{Vacuum pyrolysis:\\ 400 \textsuperscript{o}C, 60 min\\ Roasting:\\ 400 \textsuperscript{o}C, 120 min\\ Acid leaching:\\ 1 M \ce{H2SO4}, 45\textsuperscript{o}C, 20 min} &
\makecell{Leaching efficiency\\ Ni, Mo, V \textgreater 95,\\ Al = 7.63} &
FENG2022 \\
\makecell{Calcination - \\ alkali leaching - \\ adsorption - \\ precipitation} &
\makecell{Spent HDS \\ catalyst} &
\makecell{Calcination:\\ 450 \textsuperscript{o}C, 5 h\\ Alkali leaching:\\ 40 g/L \ce{Na2CO3}, 90 \textsuperscript{o}C, 2 h, \\ S/L = 100 g/L} &
\makecell{Leaching efficiency\\ Mo = 97\\ Final purity\\ \ce{MoO3} = 99.5} &
KANSOMKET2022 \\
\makecell{Calcination - alkali \\ leaching - \\ precipitation} &
\makecell{Spent HDS \\ catalyst} &
\makecell{Calcination:\\ 450 \textsuperscript{o}C, 4.5 h\\ Alkali leaching:\\ 20 \% NaOH, 25 \textsuperscript{o}C, 2 h} &
\makecell{Recovery\\ Mo and V $\sim$ 95\\ Ni = 99\\ Final products\\ \ce{V2O5} and \ce{MoO3}} &
ROJAS2012 \\
\makecell{Roasting - oxidative \\ leaching - precipitation} &
\makecell{Spent HDS \\ catalyst} &
\makecell{Roasting:\\ 500 \textsuperscript{o}C, 120 min\\ Leaching:\\ 0.4 M \ce{Na2S2O8}, 50 \textsuperscript{o}C, \\ 90 min, 400 r/min, \\ L/S = 12.5 mL/g, +75–30 μm} &
\makecell{Recovery\\ Mo = 89.8,\\ Co = 86.5,\\ Ni = 81.2} &
ARSLANOGLU2021 \\
\makecell{Roasting - alkali\\leaching} & \makecell{Spent HDS\\catalyst} & \makecell{Roasting:\\600 \textsuperscript{o}C, 60 min\\Leaching:\\0.75 M KOH, 70 \textsuperscript{o}C, 90 min,\\L/S = 15 mL/g, 300 r/min} & \makecell{Extraction yield\\Mo = 93.82,\\Al = 46.91} & YARAS2020 \\
\makecell{\ce{Na2CO3} assisted \\ roasting - \\ acid leaching - \\ Solvent extraction - \\ precipitation} &
\makecell{Spent \\ hydrofining \\ catalyst} &
\makecell{Roasting:\\ 850 \textsuperscript{o}C, 120\% \ce{Na2CO3}, 2 h\\ Leaching:\\ 2.5 M \ce{H2SO4}, 60 \textsuperscript{o}C, \\ 5\% (w/v), 90 min\\ Mo extraction:\\ 15\% P204 + 3\% TOA, n - heptane, \\ O/A = 1/1, 5 min, pH = 0.65\\ Al extraction:\\ 50\% P204, O/A = 2/1, 20 min\\ Ni precipitation:\\ pH = 7, 140\% \ce{Na2S}, 30 \textsuperscript{o}C, 50 min} &
\makecell{Recovery\\ Al = 97.5,\\ Mo = 95.5,\\ Mi = 90.9\\ \\ Final forms\\ \ce{MoO3} (pure),\\ \ce{Al(OH)3} (pure),\\ \ce{Ni(OH)S} (pure)} &
CAI2022 \\
\makecell{Acid leaching -\\crystallization -\\precipitation} & \makecell{Spent\\reforming\\catalyst} & \makecell{Precipitation:\\0.3 M \ce{H2C2O4}, pH in 1.5 - 2,\\\ce{C2O4^2-}:\ce{Ni^2+} = 2:1, 60 \textsuperscript{o}C, 1 h\\Drying at 110 \textsuperscript{o}C for 4 h\\Decomposition at 600 \textsuperscript{o}C} & \makecell{Recovery\\Ni = 98.5,\\Al = 40.7\tnote{a} \\Final products\\NiO (purity 98.3\%)\\\ce{Al2O3} (purity 99\%)} & abcd
\\* \bottomrule
\end{longtable}
\end{threeparttable}
\end{landscape}
\end{document}
